Look into an 18650 LiIon LED flashlight. They are small but powerful, and totally reliable. It is my EDC light.

If you get NMH 9 volts, they will last several thousand charges. Most are actually 7.4 volts, but they work in all gear I've found.

I've got some sights that work on the CR123 batteries, so I've stocked some in; but I plan to build an adapter to allow 18650 use. Everyone's path is different, so just keep on prepping!