UR crazy /ubbthreads/images/graemlins/yellowlaugh.gif, although messing around with lights is often as fun as using them. The UK dive lights are already pretty cheap, so I think you would have a hard time buying parts and doing it for less. Then again, if you are going after a 35-50 watt HID dive light, then that sounds like fun. Welch Allyn sells the 10 watt HIDs.
cheese