Look at nocturnal lights overvoltage halogen system - a bit bigger battery, but bulbs are everywhere from 25 W to 50 W, narrow beam to flood - FOR $6 AT YOUR HARDWARE STORE!Twomixdiver:I think HID cannister light technology still needs work; regardless of brand. I am still turned off by the cost of replacement bulbs. Even Spoon's Salvo battery charger crapped out on him in less than a month. And I've rarely heard of an HID owner who didn't need to replace his bulb in less than 18 months. So if you really want an HID light you'll have to factor in the cost of a spare bulb in your purchase.
Unless you're a person who likes fussin and babying your dive equipment, I think this type of gear takes too much out of the BASIC fun in recreational diving in its PRE-DIVE and POST-DIVE task loading.
But on the otherhand, if you're a fulltime caver, then its another story.