no doubt the h sounds better, but people say the dr.gas is the closes to sounding like an h, so if the power is that much better for the x that sounds like an h, then BAM, u got gold
O/R - Dr. Gas. Dyno Proven to be the best.
Catted - Magnaflow or Bassani.
I have a bassani catted X pipe, and I love it. Sounds good. good performance, no complaints. However, I am a big fan of matching, so i would go with the magnaflow because you have the magnapacks. A friend of mine has the magnaflow catted X with magnapacks and it sounds pretty good. Any of these three i think are a good choice.