Norman's Lights look awesome and are 40 for bullet headlight (nice!) and LED tail lamp with chrome bezel.
If you are DIY type, you can visit a track lighting store and see how bright 6v 10w and 5 watt MR11 bulbs are.
I'm using 12v MR11 small lights in a PVC plumbing connector, with battery pack. These are pretty bright, but use the spot beam if you can get it or narrow flood if not. see
I do not know how much Wattage the motors can produce on the white wire, but I know that a better ground will make your lights brightest possible. These MR11 bulbs should not be run at very dim, but can dim and brighten without damage (track lighting!)