I'd recommend calling JonB at the Parts Rack (site sponsor). I spent over a half hour on the phone with him reviewing all of the options. I decided to do K&N with smooth tubes and a belanger cat back exhaust, so I went just part of the exhaust first. I'll see how I like this setup & then I can move to the belanger headers, built to go with the catback, whenever I want (& have the extra $). JonB said belanger specs 50 hp with the header & catback installed, that would make me very happy - I'll see.
But, I'd talk to him, great info.
Dave.