Before actually buying any lens, I would like to suggest you to rent/borrow a lens first, test a lens for a few hours and it will help you to decide how long is long enough for your needs.
You know your budget and your needs, you also know that you need a fast/bright lens, if you know your desired focal length then you can take a look at online shops such as B&H and Adorama to find some lenses within your budget. I usually use B&H website, their filters are really helpful, even if you don't want to buy from them. for example check this search result, I rounded the price to $1800 and selected Nikon and few other good third-party brands, all you have to do is to check your desired focal lengths.
Now take a note of the lenses that you like and check photozone.de for lens reviews! also don't forget to look up the lenses on Flickr, just search for the lens name plus the type of photography (bird, sport, portrait...)
Also FYI, all current Nikon lenses are compatible with the D7000.