I get your logic regarding the harness.... As far as a regulator/rectifier, you may want to check out this thread -
upgraded regulator .
It's a few shekels more than a used one from Pinwall, but if it delivers as promised it would be worth it.
As a matter of fact, I ordered and received the kit already. When it finally gets above freezing and I can install the thing, if it works out as promised, you can have my stock one for free if you still want a stock one.
How's that for a deal?