That flush mount rear light setup is pretty slick - where did you get them? I couldn't bring myself to put a utility light hanging down from the rear bumper because I know I will tear it off as soon as I get it mounted.
Actually they are a rubber grommet trailer light grommet. (Drilled with a 4.5" hole saw) and 35 watt 4" headlight bulb. They just push in to mount them once the hole is drilled. A good parts store will have a 4" headlight bulb and the trailer grommets. I think all in they cost me $16. They should be bright enough to see from the truck mirrors when backing up and well protected.
Also the grommets allow you to mount the light in a spot that is not truely flat as the bumper itself has some curve to it but it holds the lights very well.