just buy a catback system. any gt catback kit that will work for your car's year will do. then go to
www.americanmuscle.com and buy an h-pipe adapter.
just tell them they have to cut the y pipe and bolt the h-pipe adapter up and the catback bolts up directly with no changes needed.
they put universal hangers on mine instead of using the ones that came with the h-pipe kit. you might want to talk to them about that.