should fit anything, b/c almost all aftermarket cat backs can be used on stock H's so any aftermarket H would half to emulate the stock one... basicallly YES!
no matter which off-road h pipe you get, its going to sound the same as they are all the same design. the mufflers make the difference. at that point it comes down to preference. Flowmasters create an aggressive sound but often are accused of coming off as "tinny." MAC mufflers IMO make a spectacularly throaty sound, but when combined with an off-road H, they "rap" too badly. I would only combine MAC mufflers with an x-pipe. (a friend has this setup and his car sounds MEAN) i am not personally a fan of magnaflow mufflers, but some on here swear by them. dynomax super turbos sound like junk but their ultra-flo muffler is pretty nasty. bassani and borla both sound good but are very pricey. those are the most popular ones, but if one thing is for sure more mustangs have flowmasters than any other muffler. that is because they sound good with almost any exhaust setup and the cost is reasonable. any cat back will bolt up to any midpipe.