Jeff, some of your listed mods (turbo and 1 bar w/g spring for example) will mean that you will have to increase/alter fueling (aka: CIS mods). This would be easily done with an adjustable WUR/CPR, but unfortunately, no one is currently making those and they sell almost instantly when used ones come up (as you noted). I can't say what your options are other than to watch eBay and the PP classifieds like a rabid hawk!
The need for increased fueling with the above two mods is . . . the GT35 turbo will still be blowing hard (like Paul) at the top of the RPM range whereas the 3ldz is long out of breath by then, and the 1 bar spring increases the engine's effective compression ratio (and creates more intake heat) than the stocker, so more fuel is needed to lesson the possibility of detonation.
By the way, "keeping it stock" is for posers and pantywaists (except for installing 18" wheels as that's just gay)!
