I believe Rallylights, or Susquehanna motorsports (same company) has the only truly legal hid lamp replacement for the jk. The bi-xenon is the hid kit you would be interested in, not the hid kit. Why? Well, as standard hid kits go, they usually have no low beam, and in some cases use an incandescent bulb to act as the low beam and the xenon bulb acts as your hid.
Further, hid "kits" or "retrofits" can be dangerous and produce light in a pattern that can cause a lot of glare for other drivers and pose a hazard while driving. This is because the housing used to retrofit the lamp is meant to be used with hid. Hid do not use reflector but rather a projector housing to give you that clean legal cutoff lines that hid lights are famous for. That is why when you see ricers with cheap DIY HID kits their lights blind the heck out of everyone.
The bi-xenon hid headlamp, as far as legal ones go, and I believe SMS has the only legal one out right now at a hefty $1400.00!!!!!! (But correct me if I'm wrong if there are other bi xenon out there) gives you a low beam and a high beam! This is what makes the hid lamp bi xenon, is that you get a low and a high beam. This is achieved through a lense or filter that drops down to block half the lamp to give you a low beam. The lense then raises to give you high beam. Bi xenon.
Now having said all that, the light output is amazing and nothing else really beats it at the moment, however LED technology comes in a close second place. The ONLY two things that would ever keep me from buying a set is the price point at $1400.00 and the fact that I personally think they look ugly, however that is being subjective and not objective as headlights are not meant to be looked at but rather looked with. So there you have it sir, my 2 pennies!