if you are looking there.. I would stay away from those specialized batteries. I do not know about the one, but while you can get 123 cells at the store, they are -very- expensive for what you get.
I get my flashlights for work from LED Bright Flashlights and Rechargeable Flashlights by LED LENSER
. I carry the "P7" and most people who see it light up for the 1st time remark on how bright it is. They also make larger and brighter lights along with smaller. I chose the P7 because it fits in my beltholster with my multitool
I agree that you should have some AA battery powered flash lights, and possibly AAA. I also think you should have several and if you need bright pocket-able lights there is no substitute for the higher voltage batteries. I like the 18650 because they are easy to recharge and can substitute 123 cells though when bought in one or two packs they are expensive. Not so bad if you buy in bulk packs. I avoid the Rechargeable 123 as I have not found the cells to have very long life. But you need several lights in my opinion, as they can go overboard. A good site for some fairly well made LED flashlights is Cheap Cree Led Flashlight Torch on Sale at Dealextreme - DX
but it does take patience as they take a while to delver. They have button cell key-chain flash lights for 10 for $5 and I like to keep them hanging all over the place. They come in very handy even just looking into a locker. I think it is not unreasonable to have at least 5 flashlights on board, as you know you will drop one or have dead batteries in at least one!