the answer depends on a few things...
1. how much are you willing to spend?
2. what shape? pistol grip, flashlight tube shaped, or a suitcase style handle-over design.
3. instant-on incan or HID (HID has some great advantages, generally brighter options available, longer run times/more efficiant, nice white light. but incan reaches full brightness in miliseconds as apposed to most HID setups requiring several seconds to reach full brightness)
I'll make a suggestion though... Maxabeam. $$$ ehe.