exhaust!!!!

hey guys, i finished installing my place racing cold air intake, of course with your help. now i need some more help with what kind of ehaust should i get for my 01 sentra gxe. im considering a tanabe universal exhaust but is it that nice and are there a lot of gains? if you know a better exhaust please tell me. i have a budget of around $500. but of course i want a cheap one that will really show imporve ment.i want to do this asap. thanks!!!