Let's not forget the Cardoc special... It's been so long since I've been on the sight I totally forgot the fellows name (nice guy too), but his Contour.org username used to be Cardoc (just checked the userlist, if he's still around, that's no longer his name). Anyway, he did a custom job, bought two tips (chose your poison) and a single center inlet 2.5" to dual outlet 2.25" which would then be placed where the stock resonator currently resides. Then there's be duals from the muffler (roughly middle of the car) back. This produces great sound, and opens up the exhaust, but not too much. I have the parts, but still have yet to do the job. Parts were about 100 for a Flowmaster muffler (it's basically a metal box with a triangular metal blade to "muffle", it really just tunes) and two SS 3.5" tips that I found on sale somewhere. Labor will run me somewhere between 250 and 350, that's what I've been shopping around for. So it's pretty close monetarily to buying a prefab system. Of course it'd cost more to get this custom job mandrel bent. Considering how open this custom system is, I don't believe the crush bends are that much of a negative point (might even be good for maintaining back pressure at lower engine speeds). Someday I'll get it done and I'll tell the world (also record it and put it online).
Anyway, just another idea to add to the pile.
Chris