Have fun: H11 HID kits | H11 LED bulbs | H11 automotive bulbs I went with LEDs personally, but I remember reading a few people in the "What have you done to your c today?" thread went with xenondepot.
HID kits are going to be a pain in the nice person to install, like DJDawn I went with LEDs and I'm quite happy with the result. The only downside is they don't generate enough heat to melt snow properly.
HID kits are super simple. I bought mine off ebay for around $30 about 8-9 years ago. I've had to replace the bulbs once, but I bought the ballasts on my 2001 Saturn and transferred to the Prius. Just make sure you don't get the slims, I've heard nothing but complaints with them.
Make sure doing this is actually legal in your state. I know its not here in Washington. Posted via the PriusChat mobile app.
Probably depends on the color and intensity, but I don't know as I haven't looked honestly... besides, being against the law never stopped people from speeding before.