We had someone visit CCHS (I think either he was from Brisbane or moving to
Brisbane) with that same setup.
From what I remember, he bought a halogen light, ripped out the halogen
holder and put the LED's in there himself, with an added battery pack in
spare space, and chucked a switch on the back.
It was totally homebrew, not bought off a shelf.
Stuart Young (aka Cefiar)