ask Rick (mentioned above) he does a superb job building these things. Your gonna pay a hefty price for these, but dont worry though, your going to get a quality set of lights, legitimate projectors and all that best stuff, none of that cheap crap aftermarket companies make.
I did a Morimoto D2S projector retrofit that I purchased from Matt from theretrofitsource.com - It's pretty easy to do on the big 4Runner glass headlamps that are easy to remove from the car without even having to take bumper off. Getting the horizontal alignment took me the longest amount of time because I wanted it perfect.