Yeah, you'll find that there are generally two avenues most flashlight junkies go: buy a light and mod the hell out of it, or buy the parts and build one from scratch.
A third avenue exists if you have the engineering expertise and access to the required tools: machining your own flashlight parts from billet aluminum. However, very few of us here have the tooling and know-how to do that, so the next best thing is to get a pocket-sized electronic enclosure and stuff batteries/LEDs/bulbs/switch/etc. into it.
oO