Join Date: Mar 2013
Location: Montreal, Quebec
Ah, yes. I agree with what blu3_v1p3r said. If you're looking for anything other than just sound, you will be disappointed. The muffler is just another link in the chain. If you strengthen that one link, the chain will still be weak. That is what's known as the bottle neck.
Best bet is a complete header-back as stated above. That means a header (shorty, midlength or longtube), downpipe (w/o or w/cat), and a catback. All your bases are covered and you'll see the most gains across the board. However, if your car can't draw breath, even a perfect exhaust will be limited. A CAI/SRI would be highly advisable along with an upgraded throttle body and intake manifold for support. Without touching the engine, you won't get better breathing then that.
Do you plan on tuning?