So in the absence of answers I have decided to ask the audience, knowing I will get votes on every answer. Hopefully I can tell which answer is the loudest.
At high altitude we have a unique problem. My 2.5L STI behaves more akin to a 2.0L EVO than a sea level STI. I made the mistake/choice to overboost my VF39 to 19-20 psi. At 5500 ft, this is a pressure ratio of 2.6-2.7, which is out of the range of the only noncompressor unmap that is available online. I now am blowing smoke worse than Cheech and Chong.
Since altitude robs flow but allows higher boost due to lower absolute manifold pressure, I want to find a turbo that won't surge and allows high PR, preferably with ball bearings.
My input conditions-
2.7-3.0 PR boosting between 3000 RPM and redline.
Depending on the calculation that is between 15 lb/min and 39-42 lbs/min.
The turbos I have found -
EVO 3 16 G
Garrett 2871R, 3071R, and 3267
T04E super 50 trim
I have looked at the 68HTA and PE1818 posts, but without information (compressor map) I won't spend the money.
Does anyone know any others that will fit this range? Please don't say 18-20G FPGreen etc. If it is too big for the altitude, I might as well walk than wait for the spool.
Also, I'd like to know if anybody has found a T04E super 50 bolt on turbo for a Subaru. There doesn't seem to be one available anywhere. I don't really have $4k to spend on a rotated mount, and I definitely don't want an FMIC.