Why don't you like the portraits from your kit lens? you should take a long hard look at your pictures and decide exactly what it is you want to improve.
Then you should try to solve the problem without getting a new lens - if you ask here how to do something specific with your kit lens you will probably get a good answer.
Only when you are sure it's a lens limit you buy a new lens - or lighting equipment or whatever you need.
A portrait is mostly about posing and lighting, it's unlikely a new lens will automatically improve your portraits (on the other hand new techniques tend to offer immediate improvements)
And about the macro (that should really be a different questions) a real macro lens is best, the filters are pretty bad and extension tubes and reversal rings are both good, I would get a cheap extension tube set to experiment with but a reversal ring will also do the job (I'm just a little nervous about exposing the back element of my lens, but that's just me)