so what I'm seeing is, a slightly better/faster spooling, 400 hp set up.
I'm assuming by stillen intercoolers, you are talking about their side mounts.

I have yet to see anyone make over 400 whp with side mounts.
the very few that have, aren't doing it safely.

That rebuild kit you used for the wiesco pistons and eagle rods, if assembled properly, ought to make the engine strong enough to handle over 600 hp, (most of the time, they advertise they can handle 800) but your turbo set up isn't going to handle that.
So if it was my car, dyno time, money and hopes on the line, I wouldn't hope for more than 400.
And for the record, "hybrid turbos" is a ricey 300zx term, not a commonly accepted term, Nissan or not.
I've seen people loose power with the over bore. My 2 cents, unless you're shooting for some big power numbers, all it is going to do is help spool time. Same with that 5 angle valve job you had done. Those kinds of things don't really help until you start getting into the big numbers. You can do bolt on stuff, front mount, etc etc and get 400-450 with stock internals.