I do not suggest ever going with a 55watt ballast and bulb combination, because over time it'll burn out the inside of your projectors and then you have to cough up 550 or so bucks per headlight unit.
Go with 4500k XB35 bulbs and 35watt XB ballasts and you'll have more than enough light on the road. Roughly 2.5 times more than halogen can ever put down.