This will be my last preaching and I will let this be but drive a car with a HID kit in a stock halogen reflector housing and then jump into one with at least a projector and let me know how the light compares. Call me a lighting snob if you want, but blinding oncoming drivers is not something I recommend and aiming the lights so far down negates most of the purpose of HIDs anyway.
OEM HID's are 35W systems and you can get a 55W system from a lot of places. I use 55W systems in my 98+ bird headlight setup and it performs extremely well. Comparing a system versus another with the same wattage will be simply a contest of how the light is controlled and projected outward (sans any other factors).
Up to you in the end but I would get at least a projector housing before I toyed with throwing some HIDs in them.
Drop in for halogen housing -
Proper HID setup
