If you didn't pay much for that flashlight, then you'll have to have a heatsink made by one of the machinists here on the forum.
Also you should check the breakdown of the flashlight to assure that it dissembles in a manner that is conducive to soldering a driver.
You could always just buy a flashlight shell from dx.com for like $10
But whether it's worth it to break that flashlight down... I guess it just depends on your budget
I'd just buy a host with a heatsink from someone on the forum.