This is the light I recommended.. It gives you a wide choice of cells to use: AAA - 18650 and CR123.. The link above is similar light but is much smaller and only uses cr123's, the light linked above is ideal for a helmet light..

The beam is also adjustable which is very nice and the flashing mode is very useable, not seizure inducing like the fenix lights

http://www.shiningbeam.com/servlet/t...h-C8-II/Detail