Heya George and Dave,
What I think we got here George, and this is speculation on my part, but I think Dave is looking for that 'cool blue' white, as opposed to the 'ole yeller' white light for his headlamps.
I have a HID system on my '53 pan, due to the fact that the stock system for lighting is too much for the charging system on my scooter. I went with the HID due to the fact that it is a far better system for the application I used it for. This is for a non-halogen stuff.
Like Barry stated man, these things things are NOT cheap for start up or maintenance. You are gonna get awful p*ssed when you lose a light from road debris, ya dig? A 'true' HID system is like the florescent tubes in most offices. You have a glass enclosure with the gas inner that is excited via a high voltage ballast. So in essence you are getting a ballast and lights to make that pretty blue light happen.
Here are a few places to look, even if you don't like the improved halogen ones out there:
www.hidkits.com
www.eautoworks.com/html/lbu-Light~bulbs-Heliolite.htm
www.powerbulbs.com
www.lightlens.net/bulbs.htm
Another bit to think about, there are cheap bulbs that say they are Xenon, but they are not HID, so beware of that. In order to have the right ones, you'll have to buy a ballast to run the real deal. The others are aftermarket junk that say they plug into your exsisting vehicles lighting system. Most of the time, they are not DOT approved and have no true reference point and are marginal at best for focus and clarity.
Be careful for the 'too good to be true' and you'll come out on top.
-Charlie