yeah, what you know, is you know right. But that you also have to do for any other "swap" in Nissan EFI one. And with current technical circumstances, re-build is a completely no-go. B14 would love to have QG18/16, but it will be a long task in terms of wiring - that's right as well. Easiest option is to swap GA15DE, originally came in B14, find it in shersha, u'll find plenty, just look for a good complete, uncut, grip to grip, till battery terminal, generator wire included engine wiring, and find my thread on wiring of GA15DE.
Enjoy.