I wired lights with the very resourceful assistance from a good friend.
We used a fuse box from a junked vehicle, mounted under the hood and ran lots of wires into a switch box I mounted on the roll bar over the steering wheel. I installed 10 lighted switches I got from a auto supply store for about $2.50 each. Gives me some extras for future use. Also, be aware there are several types of lights...narrow beam, broad beam, etc....be sure and consider what your needs are and get the ones you need.
one option, albeit somewhat pricy, is a GOLIGHT
Golight Stryker™ :: Remote Controlled Searchlights
it's really cool...full features include
magnetic mount base
swivels/rotates all around vehicle, up and down
wireless remote controls, one dash mount, one hand held.
exceptionally bright, I think it's switchable between flood and spot light but need to verify.
Imagine being able to place it on roof of your RTV, go down the road and remotely have it rotate/up down to your desire using dash mount control. Then get out of your RTV....BUT cow/calf runs out of the light...use hand control to have it move back to the animal...I'd consider this level of control a safety feature, shows you tripping objects, etc. while out of your vehicle...
Best of all, done properly, you can remove magnetic mount from RTV and put it on top of a pickup/whatever and get same features....
Wish I had one, may get one...