Get rid of the cats. I like the X pipe sound, some like the H, some like the pro-chamber. Its very subjective. Once you ditch the cats you'll hear that sound you are looking for. I had shorty headers into an X into Flowmaster American Thunders and it sounded bad azz. Its really up to you.
I like the X or the H, and think the Pro-Chamber sounds like crap, but people on the board will disagree with me....... its really subjective to the owner. But you gotta ditch the cats. More air flow over the muffler = better sound.
Adam