Flowmaster sounds awesome, but not always the best flow to be perfectly honest. I have gotten good results and noise with just your standard cherry bomb style glass pack. OR just the cats with straight pipes and a hollow muffler case which I know from personal exp is awesome and not even that loud....but you didn't hear that from me :-). Good luck with it though, it sounds like you have what it takers to seriously beef one up, post a vid or something when its up and running