HID conversion kits are illegal if your car didn't come with them as standard (In the UK). You might find them hard to fit and adjust too.
Here is a colour guide:
http://www.harrisonmotorsports.com/s...hid_colors.jpg
If you can't read them they say:
4.3k -> 6k -> 8k -> 10k -> 12k.
Note these are not power ratings.
Also bear in mind you may fail your MOT if you have these in. Best bet is the get the white ones (4.3k).
Cripple.