I live in the UK and as I have only a few recommendations for legit, good battery stores (suppose I could find more but these do fine) so I get awt 18350s for some mechs.
They're 10.5 Amps (I think, please double check) so they are fine for my +ohm builds.
However, I only know of a few regs which use 18350s which is great. If you are using a mech, you should do a little more research. Make sure you know the ins and outs of battery safety, follow some of Mooch's battery safety info and look for baditudes mech mod safety info.
Best of luck