Ok,
Metal halide bulbs,(Also a HID bulb) like is used in a school Gym, take up to 2 mins. to cycle up to full bright.
Metal halide lamp - Wikipedia, the free encyclopedia
Another is a bulb used on a LCD computer projector. This is also a HID lamp.
HID is great for light output and power used. Thats why they are so bright, but the down side is the ballast warm up. During the warm up, The color temp will change from blueish to white. It would be hard to turn on a high beam with the same color as a low beam and have them match. You can get a halogen bulb that is colored to a higher color temp and that will make them closer to matching.
I would get just the low beam and you can later add the high or fog/driving light in HID. You will be shocked on how much light you get with the low beam only on a 4300K or 6000K kit. I know the higher color temp kits will give up light output because you are restricting the total range used. Think of it as a speaker and only using the high frequency tweeters in you car.