well if it's sound then you don't really have to worry about the full exhaust system. I just listened around till I found kinda what I want and plan on getting a magnaflow muffler to see how that turns out. I'm hoping to have it within a week or so and when I figure out my results I will update you.
2006 Pontiac G6 Sedan 3.5 V6
Mods: Drop in K&N Air Filter, Partially debadged, Vinyl overlay on door trim and darts.
To come: Ehaust, Tint and much more.
Well congrats on getting out of H.S., off to college in the fall? As far as exhaust goes, to get sound you are going to change your performance making it either worse or better. If you do not have back pressure you will loose bottom end but gain top end, so you need to find a happy medium. Best thing to do is look around see what you like, go to an exhaust shop and talk to them about it, then order your mufflers and tips. check out you tube, there are a lot of G6 GTP's with systems posted on there