Just wondering the best way and what it would cost to get a better sounding exhaust on my '01 SE, for a bit more performance and better gas mileage. I would like to have duals because of the look, but its not necessary.

For sound buy an aftermarket muffler (Magnaflow or Flowmaster), it should cost about 110 for both, not quite sure how much to have them welded up. You wont see much gain in performance because we have a pretty free flowing exhaust from the catback. Your best chance for any performance gain from the exhaust would be to buy a high flow cat, they usually cost about 70 on ebay. I'm not sure if header'* will help any, but I know someone with more experience will chime in

A high flowing CAT will be a slight improvement, but anything past that is for sound only (no performance gain will be achieved). However going with headers helps a lot on the 2000+'*, but really is not worth the investment until you build up the engine first with rockers or a cam.

Usually the more free flowing air you can pump through the engine the smaller the supercharger pulley you can go with, depending on KR.