[Halon]

35W is pretty standard for HID headlights, it's all I've ever used and what a majority of people use. If you want to run 55W, you need to consider the extra heat that will be generated from a higher wattage bulb. Not sure if you're just going to do some kinda PnP in your stock housing, or a projector, or what. But if you plan on running 55W bulbs, you should make sure the added heat isn't going to harm your housing/projector. Also higher wattage output means you need to consider the added power input required. If you don't plan on upgrading your stock wiring, or run a relay kit, that means you are going to be asking a bit more from your stock wires which may not be capable of safely taking on that added current required to run a higher wattage system. Don't want to add your name to the list of people whose cars have burned down due to improper install of aftermarket HID kits do ya?

So in a nutshell, just get 35W kit. A 35W kit at 4300-5000k is perfect in my opinion. 6k starts to get blue to the point that people will know it's not stock HID's. And anything beyond 6k screams ricer!

And I highly recommend getting a relay kit as well, even if you go with a 35w system. Reason being is that the immediate in-rush current required to "ignite" an HID bulb is significantly higher than a standard Halogen bulb. Once it ignites, the current draw isn't really an issue anymore, goes back down to more normal levels. But it's that initial in-rush of current which can spike pretty high. That is why you'll see the wiring is a bit beefier usually on an OEM HID car. 90% of the time people are fine sticking with the stock wiring, but the risk of damaging your wiring is there. Running a relay kit will allow you to run a larger wire that will be able to handle the higher in-rush current safer. They usually aren't that much money, so I always recommend getting one as it's a pretty cheap safety curtain.