Latest thinking...
Continued research seems to be narrowing it down to two or three lights:
* Lenser LED P5
* Maglite LED 2AA
* Streamlight Task-Light 2AA
Lenser P5
+ single AA (compact), high output, adjustable focus, 3watt Cree
- runtime may be low (using my rudimentary math!), unregulated,
Maglite LED
+ 2xAA (bigger fuel tank), adjustable focus, waterproof, 3watt LED, regulated, reasonable run-time (given the regulation)
- still not quite the run time I'd like, know nothing about lumens output or throw, body length
Streamlight Task-Light
+ 2AA (fuel tank), Hi/Lo power levels, excellent runtime, waterproof
- relatively low output (but maybe quite sufficient), unregulated
The maglite crept into the equation when I found it during research and seems to get quite good review, cheap enough here in UK, too. In fact all lights mentioned can be bought for under $28 equiv. (note: my price observations suggest we generally pay 33% more in UK for any given model)
Decisions, decisions....