The HIDs should only be used with clear leses. If they are "lined" lenses then it diffuses the light and messes it up. The HIDs you get on eBay are a straight replacement. They plug into the stock light source and don't put any extra strain on the wiring as the wattage is lower than normal Halogen lights. Think its like 35w but 20kV or something like that. As for aiming, mine followed (exactely) the light pattern that my halogens had. But the light output is seriously, and I kid you not, 2000 times better. Even against my "super white" halogens! I was happy with my halogens until I got my HIDs
Mine was not a "boy roy" modification, I went for the 6000k HIDs which are pure white. Non of this blue tint. Although my eyes are still not used to seeing things in colour at night, something with that just seems wrong lol