Re: Any pics of Z2 combatlight w/ A19 batt. extend
Don't have a pic, sorry, but I used an A19 on my C2 off and on with a P90 until I bought a Z3. The Z2+A19+P90 (or P91) will be fine. The Surefire/Rogers shooting technique using the "combat grip body" of the Z2 won't work if you intend to use the light alongside a handgun, but other than that, it'll work great.
I keep my C2 on me, and an A19, extra batts, P90, misc accessories in a zippered pouch in my briefcase (The Z3 pulls nightstand/house duty). If I'm stuck somewhere and need extra light, I swap out the lamp and A19 and extra batteries for the 9V setup and am good to go.
[I mark my SF batteries with a Sharpie as "2" or "3" so I use them up as a set. If I keep 3 batteries for P90 usage, I have those all marked with a "3" take the original 2 out of my 6V light (they're usually marked with the date I installed them), put them aside, and use all 3 of the "3-cell" lights together.)]