keep your 2 and a 1/2 in exhaust.
get some genie extractors (or headers whatever u wanna call them). and a hi flow sports cat or a 2 and a half inch sports cat.
take out 1 muffer, leave 1 resinator at the back, your exhaust will sound like an 8 and you will *definately* feel the difference.
the sports cat (hiflow) is roughly $340, and resinator sometimes free if u can smooth talk otherwise $50-$80. and with that, you should be sweet.
otherwise without extractors, 1 resinator at the back, and 1 muffler, will sound and go smooth.