There are lots of RCR123a's (16340) available, most use Chinese cells.
I bought 2 Elusive Wildlife branded batteries a couple of years ago and both died in year 2 of use.
The last that I bought are Orbtronic brand and they are made in Japan. One note of caution on the Orbtronic is that they are just slightly longer than a standard CR123a so if you stack them they might be too long to fit in your device. I know from first hand experience that they will not fit in a FLIR Scion because of the extra length.
I also like KeepPower brand batteries and they do sell a RCR123a but they do not disclose in the description where they are made.
I have been using 18650, 16650, and 16340 for years now and in my experience you get better life and performance with Japanese cells than with Chinese cells.