For white lights or compact flashlights, I'd check here:
www.policehq.com www.galls.com www.qmuniforms.com www.uscav.com www.natchezss.com www.actiongear.com
Most LE & tactics instructors suggest buying a white light with at least 65lum.
I'd get a newer style with a strobe feature. Surefire, 5.11 ATAC, Streamlight, and Blackhawk are very popular. 5.11 makes a new ATAK line that's rechargeable & uses the powerful Li batteries. It has strobe, red & blue lights to for low light viewing.
I'd also suggest a tailcap button or switch. This design is better for use with firearms.