Twin turbo and twin injectors are a bit out dated lately. Has it been a while since you have looked into tuning? Times have kind of moved on with more advanced ECU's that can handle large CC injectors at low idle, something like the 750cc you will most likely require shouldn't need a smaller injector for idle or anything of that nature. Twin rear mount on an inline 6 just seems gratuitous. A modern single turbo will have adequate spool characteristics or you can cheat with a QSV, but running two same sized turbos ala FD RX7, TT Supra, or the TT subaru that spool one then both at different times is quite a chore when modern compressor housings, twin scroll, QSV and such will bring most to a more than usable power bound. Most rear turbo setups are due to proximity of a rear mount engine, space, laziness, or style. Engine is in the front, you have ample space, the fabrication to mount the intercooler back there and the ducting to bring it back forward would indicate no lack of effort, so short of style it seems kind of silly.
Echoed above, find the ecu the shop or shops around you will tune on unless you have a tuner or plan on doing it yourself.