rail mount or handheld?
I just purchased one from Hong Kong (chinese supplier), cost about 40$ with recharger and batteries, using the latest LED emitters from Cree puts out 230 Lumens. One thing I love about it is a strobe feature, which blinds/confuses the **** out of the person it's aimed at...
I get about a 1-1/2 hours of use on HIGH. It's slightly brighter than a 4D mag light. And it's bout 6" long... I love it.