^^^ +1 I don't have one of their kits yet but you can't beat $30 for an HID kit. That is the lowest price I have seen so far for HID kits. DDM Tuning is your best option IMO and several members on here have their kit. There is a thread somewhere on here about their kits.
I would stick to the 35w kit. It is bright enough. and I wouldn't even think about the 55w kit unless you have some sort of projector setup or something to reduce the glare otherwise you will have a lot of angry drivers in opposing traffic.