HIDs4Less.com
autolamps-online.com
These two make the best HID kits. There's one more, I forget the URL. It's Auto-Lite, or something like that. Anyway, all three kits offer molded bases and are adjusted to compensate for 9006 filament position. Light output is measured in lumens. IIRC, the 5000k kit was the highest in output, decreasing as you increased in temp.
I almost purchased one of these kits, until I realized how much the stock reflectors suck. To do it right, you really need projectors or e-code headlamps; this results in a very sharp, well-defined beam pattern. It is especially important with HIDs, since misdirected light is a safety hazard for other drivers.
I remember some CEG'er fitting a pair of A6 projectors into the stock headlamps; that's definitely the way to go since the ecode assemblies don't fit, though it's labor and cost intensive (projector lenses + HID kit = $$$).
