Assuming they'll be mounted to some sort of rack, just run the cables along the length to the rack to the front.
Use those rain gutters to your advantage.:ylsmoke:
I also like the black tape idea.
On my Gen I have had rearward facing fog pattern lamps (Hella Micro FF) and used a standard trailer wiring harness spliced into the lights. When not in use (on road), I simply unpluged the power wires and kept them in back. When in use, I simply ran out the rear door and plugged them into the female connector (with an integrated cover) at the light.
Also, instead of using the normal/common split wire loom to sheath the wires, I instead used a braided plastic wiring loom on the wires. This way, it still helped to protect them from any possible abrasion while allowing any water to drain instead of collect.:ylsmoke:
HTH.