Help with my 2007 mustang v6

Well exhaust is all about personal preference, the big question is do you want to be obnoxious loud, or just a roar at WOT? There are countless exhaust combinations, depending on your wallet you can go with a dual conversion kit like the pypes one on American Muscle, to custom straight pipe (which I've heard hurt backpressure) or you can mix and match midpipes to catbacks. I'm personally getting a mac prochamber midpipe, not too loud but produces a nice tone. And the pypes mid muffler catback which will give you the roar on takeoff but have a pretty good rumble at idle. If you don't care as far as running cats or not you could do an off road x or h pipe, and into the pype bombs catback. Your best friend for setups and how they sound will be youtube. Also check out the sticky at the top of this page called the dual exhaust thread, I believe silverbullet did that write up. But it is very informative and should help you a lot. If you have any further questions feel free to reply or pm me. Hope this helps.