I can help you with the wiring, it is pretty simple on the 7MGE. You can either run from the Toyota Fusebox or integrate into your own.
There will be a fuel pump relay (controlled by the AFM on stock 7MGE), main relay (key to on position), and a constant 12V power to ECU so that it can remember it's last fuel trims.
If you want to go old school you can just make a switch for everything. Let me know if you need help with wiring.