I just bought a set for my mk2 this summer, then bought a set as well for my girlfriend's mk4. Best purchase I have ever made for the car.
When upgrading to an HID lighting system you also have to replace your headlights. They MUST be E-Code (European Code) otherwise they will have a spread beam pattern and blind people driving by. These can be purchased relatively inexpensively on Ebay for $160ish. Just look for E-Code.
More info on converting here:
http://www.danielsternlighting.com/tech/bulbs/Hid/conversions/conversions.htmlThe bulb type you are looking for is not H4. It is actually H4-3. The "-3" basically means with a high beam. As for type, I have 6000k. IMO it isn't worth getting the them if they are any lower than the 6000k bulb.
The high beam functions by using a solenoid to change the angle of the bulb therefor throwing the beam pattern into a higher position.
The place where I bought mine is in China. Here is their website.
http://www.vvme.com I really have no idea what the tattoo kit picture on the front page is about. Nowhere on the site is there any other reference to it... :lol:
It comes with EVERYTHING you need to install including the ballast and even a relay system. Both sets that I have purchased have worked well to date and are relatively inexpensive as well.
If you have any other questions just ask.
EDIT: I just see now that you have dual rounds... If I recall, the inners do not serve as a high beam. So you would need an H4-3 kit for the outers and an H4 kit for the inners. As well as E-Code standard headlights for both inners and outers. I think it might look funny having HID's on one and not the other.
I have Aeros so mine was fairly easy to do.
Matt