Hi Austin, Midland turbo do the gtir upgrade but they don't call it that. You have to tell them the spec you want which is-
Stagger gap oil seal
360 degree bearing
60trim comp wheel
possible 0.8bar actuator (i didn't have one on mine and didn't have any problems)
They also modify the turbine wheel to there own thing, not sure what they do but the bloke that did my turbo did this for me.
The price inc full rebuild and new core, its not cheap about £600 i think, but thats inc delivery too.
If you ring them up ask to speak to one of the tech's alot better
If you want to know if the turbo is any good then look in rolling road section and for powerstation x2 coops, my mate came with me and he had my old turbo (one from midland turbo)
Hope this helps
Ash