Nice, good to see someone else doing something with the OHC other than STOCKů
I put two switches where the three were to control each side light and converted the MAP lights to a directional LED setup. Then added a home made panel where the digital display was for four small toggle switches to run who know what.
So with what you are doing all you need is two 18-ga wires, one RED for pwr and one BLK for grd, with an in-line fuse or tap an existing circuit on the Circuit Panel. They can run up the side pillars in front or can go to the back, up the side behind the driver and then to the front (whatever way is best for you).
Then the OHC will have its own pwr circuit and IF something goes wrong you will know where to find the problem.
Luck with it.