Newbie, wondering about CRX/GSR Turbo

Hey, I just found this place on the web and I think a friend of mine recommended this place a while back. I've got a 91 CRX that just came back from the shop after a GSR conversion, I've got a nitrous system on order, and a new camshaft and pistons/rods are on my wish list :icon16: . My question is: What is the best turbo for the gsr that can also fit into my engine bay of my crx. I've been driving an imported STI that ran about 450 on the dyno, and now I wanted to move away from boxer engines and try something different (well, not really), and I need something powerful. Yea, thanx,
Peter