Nice build! I saw you mention concern over the turbo to manifold nuts coming loose. I purchased these OEM Nissan locking tabs years ago and have never had an issue since:
https://frsport.com/Genuine-OEM-T25-...ab_p_8123.html
I had the same problem when I first got my S13 but installing the OEM nuts and locking tabs solved the issue for good. It's been many years now without running into that issue again. You might already know this since I know the build is still past tense, but figured I would mention it.
Enjoying the thread- keep it going!