The exhaust shop setup is good for jsut a cat back. Unfortunately for us, most of the power to be gained is also in the downpipe and cat. Get a full turbo back exhaust from sites like
www.bushurracing.com (my favorite)
www.roadraceengineering (great DPs, but I dont care for the name brand catbacks)
Damn. Its late and I cant think of my usual list. But thats what to look for. DSM SPECIFIC shops make the best exhaust for cheap money. No brand name to support. BR exhaust are running 8s if that means anything. Go for the 3" now, or you'll end up buying two full exhausts like me
LAst time I asked my exhaust shop what they would charge for a full setup and its still a little more than a BR turboback. If you do go this route, say you buy the RRE DP, and get the catback made, use the Dynomax Ultraflow 3" in "Welded" (cheaper) or "Stainless" (more of course). Its been tested by a local guy to flow better than a 3" pipe. Why? It has a 4" inner diameter. BR uses these on thier exhausts, so it sounds just like a BR exhaust. This is what I did. I bought the RRE "long" DP, and made my own catback based on the Ultraflow Welded.
Forget the supercharger idea, turbos are superior in our applications. There is a reason DSMs are running 8s and 7s on turbos.
Also keep in mind that with a 3" exhaust you have to deal with boost creep. While this may not appear on the stock T25 turbo, when you upgrade you will have to take this into consideration. Boost creep is bad. Search on here and on the tooners site shown to you above. Search with my username if that helps. I've posted EXTENSIVELY on the topic on tuners and talk.
Same name as here, with no spaces.
Also, my car makes 400 HP at the wheels on pump gas, so you can look at my mod list on
www.posracing.net to get an idea of what I have put into the car. The built motor isnt required, but I feel better knowing its there