Stay with a carburetor or go EFI

Sounds to me like you've already talked yourself into the EFI, except for the wiring (which you're doing anyway) and your fuel tank- which you didn't mention if it was still using a factory sender/pickup. If it is, you might consider this; which would allow you to keep and reuse your custom tank:
Holley Sniper EFI 12-319 Holley 255 LPH OE Style EFI Fuel Tank Modules