[LOAF]

Why not use a WRX down pipe, with no cat and modify it to fit.

That would at least solve your issue regarding mating to the exhaust housing on the turbo and give you a nice flow into what ever pipe you want to use.

I saw scooby powered beetle that actually ran the stock down pipe.. but can't remember the detail, since it was in German.

Just food for thougth..

Also plenty of guys ditching there stock or catless pipes..
Nasico, wrxfantics, i-club, or clubwrx are good forums to check out..

I would offer my stock downpipe, but not sure if I will need it for emmissions in a few months, running one of three.
VR
Alex