Hello, I'm just answering your question about the Pypes exhaust.
I have the converter back system, that connects to the stock y-pipe. The sound is good, mellow and deep (for a six) at idle and in the lower rpms. In the higher rpms, ~ 3000 it gets higher, but not a ricey tinny pitch...more of an exotic/350Z tone. I have grown to like it...it's not deep and earth shattering like a v8 would sound, but still sounds good for a 6. The mufflers are street pros (came with the system). I know they sell the same kit with an o/r x-pipe, the power gains will be better, but the higher pitched whine will be much more noticeable, and you'll probably get more drone...that's why I kept my cats on.