Need help selecting New turbo for my setup

[momento1]

ok ive got a dilema
Looking to upgrade my turbo after i change my current setup.

Current setup is
GT3071 w/ 0.63 rear
Wagner reverse intake and intercooler
Wagner evo exhaust manifold with Kflange
1600cc injectors and 044 intank pump
TFSI coil conversion
EMS standalone ecu
E85 fuel
Eboost controller
7a cams

This setup achieved 307kw atw on 28 psi.
Peak boost comes on at about 3700-3800 which is great for the street.
But i want to run more boost up to 35psi

So i am currently gathering up parts to redo the bottom end and service the head with uprated springs, retainers, seals, guides and stronger valves.
Ive also purchased a set of 267 degree cams from 034

Now the dilema i have with the turbos is that i want to change over to the GTX style billet turbos. Because of my current turbo making good power i figured going to the gtx3071 would be no brainer cause it has and increase flow of 10-15% and can be used With my exisiting 0.63 exhaust housing
But i figure that i could go to the GTX3076 cause that can also be used with the same rear but with the added benefit of slightly more power as a side affect.
Only thing im concerned with is that it will obviously be slightly slower to spool but wondering if it would be that bad with the 0.63 rear or if it would just be choked by it.

Then maybe im better off with the gtx3071 at 35psi

[momento1]

worst case scenario i could look to just completely change my exhaust manifold also to a T3 type and then i would be more flexible. but cost me a hell of a lot more

If i do that i could then also look at a GTX3582 with 0.82 rear becuase i could increase timing for more low down response and coupled with E85 fuel could bring spool down to maybe as low as 4200rpm... that wouldnt be too bad for the street i think..