I use AW IMRs for my GLV mini. 16340 is a rechargable battery that is similar in dimensions as the CR123.
I am unsure if you can use standard 3 volt non rechargable CR123s in the mini. I used to be curious but I could not find the answer - and I eventually lost interest in the question.
If someone knows if you can use primary non rechargable CR123s in the mini (since its alluded on the GLV website), let me know. Good to know in case of emergency.
There are a lot of people who do not like the ultrafire charger, I personally have a 139 charger since I was not sure that I would be interested in vaping long term, and did not want to spend $50 on a gourmet charger. I plan to upgrade soon since I have decided to stick with vaping and do enjoy it. I am upgrading for no other reason than I like spending money on good gear if the cheap gear has the 'potential' for ruining the equipment I invested in.
I can't comment on the build time and the hex keys, but if you don't have a set of hex keys handy you really should buy a set, its a great investment.
Finally CALL SARA. It really does work.