I was considering getting the Greddy kit in the future if i ever went F/I. I'm more of a track/auto-x type though....how fast do you want to go in the 1/4?
I don't think it'll hurt to have a larger BB turbo in auto-x though...because as I'm sure you know power doesn't matter nearly as much (and I think with a BB you shouldn't bog as badly). On a track though the higher boost levels you'll be running will stress your engine like a mofo...even if you built it up correctly (higher heat levels etc.)
If I'm talking outta mah @zz lemme know

, but this is what I've generally heard from the autox/track crowd.
Shingo