Slightly different muffler locations, but our '04 CVPI sounds great with no resonators or rear cats and stock mufflers. A nice cop car howl!
It does have an H-pipe, which is known to give nice low-end torque (it does!). An x-pipe is more for high RPM HP. Since you are stock, I would go for the H-pipe.
Don't get cheap mufflers, they will sound cheap.
97 T-Bird LX 4.6 - 80k miles
94 Supra TT Auto - street/strip car
04 CVPI- Brenda's car - 76k miles
95 T-Bird LX 4.6 - fully optioned, owned 15 years, 220k miles
96 Cougar XR-7 4.6- Brenda's car, owned 11 years, 187k miles
88 T-Bird 3.8 - first T-Bird, owned 5 years, 206k miles