Best Pipe Set-Up For My Catback Flomaster Set
 

I have a 2001 GT coupe with a 5-speed tranny, and a Flowmaster catback kit on it with a stock pipe set-up and american thunder mufflers. I want the car to have a better sound, I heard the offroad X-pipe can be used along with the flowmaster kit I have on the car now...Regardless what is a really good set-up for great sound and handling?