Just bought a pair of these:
http://www.jcwhitney.com/autoparts/P...010204/c-10101
A review says they're equipped with wiring and switch, and also 50 watt MR16 bulbs.
ouch... 50 watts should be too much, so I'm planning on buying 20 or 35 watt bulbs and then replacing them.
I'm looking around for an SLA battery that is 12V 7Ah so I can get 2.5 hours of battery time.
I'll take pictures of the setup when I'm done!!
Ooh - I'll need to figure out how I'll mount them also. That'll be a challenge.