If you call yourself a shade tree mechanic then you don't need a BMW mechanic. Do your homework, e.g search the forum. Several ways to do what you're after. Probably easiest is using the HexCan to power the accessories you're looking to add. Another good source is Skene, they have the controllers you'll need and various wiring diagrams readily available of their website.
Duane: '12 K1600GT/WL EngineBars//Wilbers/VarioLevers/ cbdaneAmber /BajaDesigns LED/PDM60/Remus Headers/GPR Exhaust/BST Carbon Fiber Wheels