Any H4 bulbs you buy on ebay are crap. If you go HID make sure it comes with the tranformer thing that bumpup the wattage to the bulb. And Make sure the lenses can handle the heat.
As far as adapting existing ones, there was a person on here that adapted (can't remeber exactly) some prototype ones the he go some how. Might want to search.
As for me, I'm gonna adapt some Yamaha R6 (2003) headlights to mine, or at least try to since I'm going to attemp to build my own fenders from fiber glass.
Edit: Oh I only read half of the post when i typed my response. Good work, looks awsome.