Candlepower... Arg Arg Arg!
If one decides to source individual components rather than buy a "kit" from one of the light suppliers, you still need to get basically the same component types that are being supplied by the "kit" vendors such as duckworks or xevision.
I went to GoHID as suggested and only found D2 style bulbs.
So far, the recomendations for aviation use are to use D1 style bulbs that include starters internal to the bulb assembly. The D1 high voltage (read possible radio interferance) starters are enclosed in an faraday cage at the back of the bulb to reduce any interferance issues. The D2 bulbs use external starters and as a result present a fairly long lead with high voltage pulses leading from the ballast to the bulb.
To continue on the subject of rolling your own HID's, don't be fooled by the internet snake oil salesmen that promote HID conversions with halogen mounts to fit in your current halogen reflectors. The optical focal points are not right. Application of an HID in a Halogen reflector will not necessarily get you the light output you are looking for. It will be wasted in an unfocussed dispersion. Also , the bulbs provided are all hacked up D2 units with new bases glued on. There are only 2 reputable automotive HID bulb manufacturers. Osram Sylvania and Phillips. Neither makes HID bulbs to fit Halogen reflectors.
Lastly, you want a D1S bulb. The S indicates there is no paint mask (for low beam applications) on the quartz bulb surface. The D1R bulbs have the mask.
If somebody finds a cost effective spot beam reflector that fits a D1S bulb, let me know because the rest is certainly easy to obtain new from Osram at at about 1/3 of the advertised kit prices.
