I have a similar set up, and used to have the same injectors. As far as turbo selection goes, the compressor side is based on injectors. Exhaust side is what controls spool up. The issue with manuals is it is harder to load the engine in the low RPM's when it comes to both tuning, as well as the actual mechanics.
Most people I know and have talked to with higher performance 6 speeds tend to go with the same turbos as the automatic guys, but go with a smaller exhaust housing to increase the rate of spool up because it will raise backpressure a bit and spool the turbo faster.
That being said, if you can afford it, go with the gtx. The ball bearing will spool a bit faster than a journal bearing (notice I said a bit, whether it is truly noticeable is debatable) and see how you like it. You can always buy a tighter exhaust housing for it later on if you dont like its manners or feel like it spools a bit slow. I know with my 468 and the 1.10 housing, might will spool around 1750-1900 depending on speed and gear, but it doesnt really take off until about 2100-2200. Once it builds a bit more boost though, hold the **** on. Probably going to buy a .91 housing for it soon and swap it out, just to see how it effects it, as well as hopefully increasing the responsiveness of the turbo so I can build boost back up faster after a shift.
