1. No! Its not unreasonable.
2. Completely.
3. I wouldn't bother stuffing around with the 4k. Just go a DET motor.
4. I don't think I would push past 6 on stock internals but I can't really say much as I have never turbo'd a 4K.
5. Well 4age is the easiest way. Along with a locker, decent steering wheel and some skill :y:
6. People put CA18DE, CA18DET, SR20DE, SR20DET the options are endless. Saw a ke55 with a 1j which is hell insane.
7. Buy a cheap spare. Who cares about RWC or rego. $100 from some old gran pa. They pop up all the time.
8. Don't be stupid. 4age with straight pipes sounds sooooo much hotter than some monza BOV from autobarn.