Yeah, I do those, I usu. charge 500 bucks, I'm in norwich.
It's not a process you can rush, you don't ever, ever, EVER, want to get into a situation where you are troubleshooting wiring, after it is in the car.
It will save you so much time to take it slow, triple check all your work, and do it right the first time.
I know a kid in groton who hacked his chassis harness so badly, the car is done, it will never run, with ANY motor, hehee.
-PHiZ