I got my stock exhaust fixed (it was just a bad gasket), and instead of making a mistake and just going out and buying another exhaust without researching first. I have a pre-requisite though: it must be DAMN quiet, as close to stock as possible. Here's my plan:
-upgraded greddy 2.5" downpipe w/ecutout installed
-stock cat or carsound high-flow cat (not sure yet)
-2.5" mandrel-bent piping (what kind of resonator?)
-insert damn quiet muffler suggestion here (must have 2.5" inlet)

now until I figure out my exhaust situation, I'm sticking with stock, running a greddy kit @stock boost. Let me know what your suggestions are.

p.s.: on the 2" greddy downpipe, where does the o2 sensor go? in the downpipe or in the manifold?