For those of you who might be thinking of just dropping in a set of housings with HIDs built in, here's what you can "look forward to" as far as beam quality goes.
Pretty horrible pattern with dark spots in your beam output right where you want the light most. I'm taking these out and doing a proper retrofit, akin to what 19trax95 has done.
These are the assemblies I purchased, which required drilling pretty large holes (1" or so) in the radiator frame to fit them, and even at that they fit very poorly. You have to really work the headlight housing locking pins around to get them in. Pretty much junk.