That's going to be one hell of a car....will it be drivable on the street still?
Steve, are you asking if its driveable? or streetable?

I truly believe it will be both.
Other high powered turbo cars (single BIG turbo) that produces 500-800whp.......I don't think they're streetable at all. Since the surge of big power comes in abruptly, and kinda crazy to drive on the street. They will not be able to enjoy that power at all. These cars are really meant for WOT at the drag strip. For RWD, with that surge of power, you'll feel your rear end fish tailing.........and for FWD cars, with street tires, you'll just smoke your tires......or just have an accident ......lol
When I used to have the gt35 (400whp) on my sky.......it is streetable/driveable....but I know that I can only enjoy a lil bit of the power on short sprint........or fully get its potential on an open highway. Because the surge of power comes in above 4400rpm.
The beauty of the compound turbo set-up is that the wide power band.....and very linear in power delivery. I will basically be able to enjoy the power that your car is getting right now. We kinda basically have the same spool using gt2871 components. Your turbo might spool a tad bit faster though since you're using k04 components. Only difference will be.....on the highway, at WOT, my system will not run out of breath at 6000rpm. It will be very happy at higher rpms.
My small turbo (gt2871r) has an external wg of only 20psi. Anything above that, all the excess heat goes to the bigger turbo
so basically, I can just enjoy the 20psi of my small turbo on the streets and still be driveable

RELIABILITY????? That one....I'm not really sure..........lol