> lights to be kept long term (possibly 6 months to a year without being touched)
this is what I consider best, for a readily available off the shelf host
Jetbeam RRT-01
If I wanted to keep it without being touched, it would be loaded with CR123 primary, and a spare CR123 in a container such as this.
same here
AAA Tool loaded w eneloop in my car
CR123/16340/18350 RRT-01 in my pocket
but OP may not realize he has entered that slippery slope, yet 