A bunch of companies make turbos using the Garrett system as far as naming goes...GT, Turbonetics, etc etc.

I believe Drag kits come with a T3 0.63 a/r turbine and TO4E 57 compressor, if not that exactly then something close to that. Generally when you look at dynos of cars with a Drag kit on them you'll see that the turbo doesn't even start to spool past 3000 RPM which is a bit more waiting than I prefer. The trick is to find a turbo that spools reasonably quick but also gives you good power up top. One way to do that is use a ceramic ball bearing turbo which will spool faster than a standard-bearing turbo for the same given trim, of course that's a $550 option from Drag.