OK I am going to order an exhaust system for my GT this week sometime and need some help. I plan on ordering the MAC TrueFit Cat Back System and The Off Road H-Pipe. I am also going to get the TrueFit Long Tube Headers. The question I have is should I get the OFH Pipe,OFH Pipe (economy),or the ORH Pipe Prochamber version? Will these three things make up an entire exhaust system and what do you think it will sound like? The cat back system has the Flow Path mufflers already in it. :-?