Try getting some luxeon LED's for the overhead lights. Just a suggestion...you can always run them at less power if you want.
Here is 4 LED's on my ATV 2 blue ones and 2 red ones

1 Red 1 Watt LED should be plenty. The pic is 2, 1 watt reds and 2, 3 watt blues. I want to replace my dome lights and Tailgait lights with them, maybe even the Bed light.
PM me if you have any questions.