I installed these cheap plastic ones from Kragen's, nice and bright for only $20, plenty bright.
![](http://thumbnails9.imagebam.com/2811/21641428107944.gif)
As mentioned run a relay w/its own 12volt power source and your back-up lights will be as bright as headlights. I almost went w/100watt flood lights, but then figured it would be a bit overkill.