Best quality H pipe for 99-04's is the MRT H because the fitment is great & its made out of full T304 stainless steel. It is very pricey though. i think around $415 for o/r & $515 for catted....The best bang for the buck H pipe though is the Mac o/r H. It fits decently, quality is good, & it's only about $170.... Both sounded awesome on my Mach paired up with a Bassani catback....
Bassani catbacks sound great & very aggressive IMO. It all depends on what type of sound you are going for when it comes to catbacks....
Im glad you are going with an h pipe over an X pipe....H's sound better IMO....