Wilburforce,
I've been out of the loop as well, but can answer a few of your questions. I have the bodyguard, carried it for a while, but found it a bit obnoxious for daily use (8 seconds high, then steps down), so I understand your dilemma. Sounds like you want the Bodyguard body only which would be the "MDC 1 CR123" body on Malkoff's website. You'll have to chose "shrouded" or "unshrouded". I have both. Shrouded will tailstand. Unshrouded easier to push, more "tactical". I like both. All located under "parts" section. No need to buy the whole light.
Single 123 Malkoff bodies have the same compatibility as Surefire E series bodies, and Lumens factory 123 bodies.
Any Malkoff MDC (e series) heads will work, provided the voltage is correct. (don't use a 16340 on a 3v light)
The light you seem to be describing would simply be the MDC single 123 body with a MDC low med high head. They come in neutral or cool. Both can run a 16340 (3.8 to 9v). Don't know about runtime, but would guess about an hour on medium. (70/650/2500 amp draw on low/med/high) 25/250/500 lumens low/med/high
The above setup is also cheaper than the bodyguard. Bodyguard is fun, but really designed for quick burst.
You can put your M361 on the "bodyguard" body (123 body) using the VME and a 16340. My current "camping" light has this set up, except I use a M61WLL. Endless possibilities.