Honestly just buy the capsule (bulb). All ballast will work for any capsule. Even a 55w will power the 35w with no worries just not vise versa. Each capsule is about 35-60 bucks depends where you buy it. That's what I did with my retrofit. Had visionpro h13 hID kit. When I got the retrofit projectors I just bought Morimoto H1 Capsule for 25 bucks
Let me rephrase my last post... a 55w Ballast will power up a 35w capsule and will give the same effect of using a 55w kit but the 35w life span will be cut to half. a 35w Ballast WILL NOT power up a 55w Capsule though.