I would give Walcks a call. When I ordered my wiring harness from them, I called them first and spoke with Carl. He had stated that they make the harness in house and can make several adjustments to the harness on a per-customer basis. On mine, I ordered it without turnsignal hookups, but had them add the appropriate wires in the harness in case I wanted to add them on later on.
Their harness is top quality and Carl and Dan always go out of their way to help. I have called them on more than one Saturday morning with a question and they have always helped me the best they could.