Fujitsubo Legalis R. Combine that with a Helix uppipe and Helix JDM downpipe, you will have a very nice turboback setup.

 

There's really only one setup that I have been FLOORED by, and it is a complete solution (turboback straight through to muffler): the APS SS turboback. It has a really gorgeous sound, and with a hi-flow cat (costs you perhaps 1 hp at 6600 RPM) you get no smoke, no fireballs and a howl that will make the closest ricer crawl back in their hole and pray for an easy death...

http://www.airpowersystems.com.au/us...wrx-hoe-r1.htm

The model I've seen/heard sounded exactly like the stock exhaust at idle, just a little deeper; step on the gas and it sounds like a well-muffled race bike, Ducati or BMW -- not a tinny ricer sound, but a nice powerful roar. Nowhere near as loud as a Blitz or Fireball... Anyway, my money's already spent, I'm just waiting for my engine warranty to run down before I go get one!

They also have it in a twin-tip (it has the exact same flow rate, no HP loss) for a really stock look:

http://www.airpowersystems.com.au/us...wrx-hoe-r8.htm

It is a bit expensive, however; and it is so shiny you'll be crawling under your car to hit it with Windex every week

[edit]actually, I take back the part about it being expensive -- the APS 3" turboback is actually cheaper than the Perrin, AVO, B&B or GP Moto; in fact it is the only complete turboback I found that was under $1k.[/edit]