Start with a little humility...
Ultimately, this is about as personal a decision as it gets. What it boils down to is what you are most effective with, what feels best in your own hands, whether the precision services your needs, and what offers "extra" functionality that you think you can and will use. The best way to figure that out is go to a local store and try out the mice that are there, preferably on an actual computer (if there are laptops set up, you should be able to get a store rep to help you do so.) I can offer my own experiences, and the reasons why I've chosen what I use personally, but don't let that bias you from what you think would fit you best. Mice with extra features might interfere with your own personal style of mousing, making life harder, not simpler. Despite my review below, it is really important that you find your own comfortable fit...if it helps you breeze through your post-processing work, and you never have to fiddle, fling, or fight your mouse, your probably good. :)
Enter Shameless Plug ;P
Personally, I use a Logitech Performance Mouse MX. It fits my style of "mousing" extremely well, and offers quite a few additional buttons and features that make life easier. I've made the choice to pair the mouse with a related keyboard, the Logitech Wireless Keyboard K350, as it compliments the mouse nicely with some similar features that allow you to duplicate some extra mouse button functionality.
A rather expensive set of choices, but the way I see it...you spend more hours than you really prefer processing your photos, and as you progress through the world of photography, you inevitably end up with more capable camera gear that produces better photos an alarmingly accelerated rate, the volumes of photos you have to process only grows...and grows...and grows. You should have tools that help you fly through the hours and hours of processing as quickly as possible without adversely affecting you...or your health. A good keyboard and mouse are, in my humble opinion, just as important as the thousands of dollars worth of photography equipment. Which makes $160 seem like...well, very little. ;)
So, the mouse.
I used a Microsoft mouse and keyboard for years. Always their best, as I've held the opinion above for quite some time. They were good, and worked well, but there was always something missing. As it turned out, there were always a few things missing. Logitech is like the Apple of the mouse and keyboard world. Their products are the best of the best, elegant in their design, simple in their use, but still tremendously powerful. When I finally purchased the Performance MX I was amazed, despite the fact that it was as much as both Microsoft keyboard and mouse in the past and I was a little daunted by the price. The ergonomics are stunning, it offers unparalleled sensor resolution and precision, has never required the purchase of new batteries (it uses a rechargeable that has a very long life, plus a switch to simply turn the mouse off if you're not using it), the momentum-wheel is a thing of wonder, and it has a bunch of extremely useful extras to offer. Both devices are wireless as well, eliminating desktop cable clutter.
The MX being a great mouse overall aside, there are two features that I truly love. The first is the "zoom" button and the "Mouse Sensitivity" setting. I'm sure everyone has run into the issue where they are trying to adjust a rather precise slider, knob, or other software gizmo, and you just can't seem to land it right on the value you want. You keep skipping past it because the mouse tracking speed you're most comfortable with is too fast. The Performance MX's "Zoom" button, configured to toggle the "Mouse Sensitivity" setting, is the perfect solution. The zoom button handily sits right next to your thumb, and requires a near-effortless (the near part is as critical as the effortless there...if it was truly effortless, you'd find yourself constantly in a state of dazed confusion about the behavior of your mouse) press to switch from a wild and unruly mouse cursor to a fine tool of ultimate precision. Adjusting that gizmo to the exact value you want is a no brainer when "zoomed", and it only takes another near-effortless flick of your thumb to put you back to "normal mousing mode" (yes, official terminology here). Both modes, normal mousing and zoomed mousing, have configurable levels of precision that you can configure between 100 and 1500 DPI. The adjustment might actually be the inverse of what you may naturally think (depends on how you think about it)...setting it to 100 means the highest precision, where as setting it to 1500 is the lowest precision. Either way, high precision is incredibly high precision, and works wonders.
(Note: The default behavior of the zoom button is just that, to "zoom"...whatever that may mean for the application you are using. You can switch it to the sensitivity option with the Logitech configuration tool. Despite that, I happily refer to the change of sensitivity as "zooming"...referring to a magnification of precision.)
The second feature that I truly love about the Performance MX mouse is the momentum-wheel. Most mice offer wheels that move in discrete steps, or even if they move smoothly, only adjust whatever it is you're scrolling in discrete steps. The MX has a dual-mode mouse wheel. A small toggle button near the wheel allows you to quickly switch between discrete mode and "momentum" mode. The former is the same as everyone else. The latter allows you to literally spin the wheel and let its momentum continue scrolling for you. Personally, I find the feature to be fantastic. When you are browsing through a broad set of tags in a tool like Lightroom, with potentially thousands of matching photos, it helps to be able to blast through them just at the edge of perception, and see what additional filters you might need. Momentum-scrolling through online sites like 500px and their new "Flow" mode can also be an intriguing experience, assuming the internet can keep up with the mouse. Zooming, adjusting sliders, spinning through action/command history lists, etc. all kind of take on a different tack with a momentum-wheel at your fingertip.
There are some other handy features as well. Of course, you have your standard back and forward buttons, in addition to the zoom button. Another one I like a lot that has saved me time is the Application Switcher button. Handily situated right beneath your thumb, a light press invokes a MacOS X Expose-style task switcher. Just point to the window you want, click or press the App Switcher button again, and it comes to the front. I never really cared much for Expose when it was first introduced as it required you to move the cursor to a corner of the screen to activate, and again to deactivate (assuming you didn't want to change apps after all.) Being able to activate an app switcher with a dedicated mouse button makes expose-style application switching so much more convenient, quick, and otherwise effortless. Every button on the mouse is configurable, and you can choose what, from the available actions list (which is rather large), each button does.
Finally, a handy feature of Logitech's newer offerings is the Unifying wireless receiver and software. A tiny little wireless USB nub universally supports their Unify devices, and a single configuration tool supports every Unify device. Each one you buy includes its own nub, but you simply have to register each device with the one you already have to make it function with that computer. If you do buy a keyboard, mouse, and perhaps trackball, each one will include a wireless USB nub that could then be plugged into a laptop or other computer. One simply need take your Unifying hardware to another computer, register them with the local nub and software, and your good to go! Pretty handy for when you might need full mouse support with a laptop at home, or even want to use a more fully functioned keyboard and mouse with a laptop on a trip.
Not much to say about the keyboard other than its just about as awesome as the mouse, with more custom function buttons, and a wicked look. ;) The two belong together.
Well, I think I've said enough. Tough to get better than the Performance MX and K350, in my opinion. They completely encompass quality, functionality, ergonomics, and style, and are relatively cheap compared to pretty much...any piece of camera gear. ;-)
You should indeed make sure your mouse and keyboard choice fit your style of use. Personally, I love extra configurable buttons, as they simply give me more options to optimize my workflow and improve efficiency. If you are the type of person who enjoys simplicity, Logitech still has a lot to offer there. Their quality is hard to beat.
P.S. When you get that fifty-page email from that family friend about her stupendously excellent mothers day, complete with 50,000 photos...don't worry...just momentum your way through it!