It uses 4 x XP-L HI emitters for a total of 4400 lumens. This means a single 18650 powers one XP-L HI for 1100 lumens on turbo. Current should be a bit over 3A (per cell). So I think the 14A is the total required current when you have the four cells parallel. This is not the case I believe; I thought the cells were 2S2P. So I think if you do a current measurement you would get ~7A (divided over two rows of cells means each cell “feels” 3.5A).
Anyhow, NCR18650B should be fine, although I personally don’t see a good reason to use these these days even for such a light. I’d go with something like Sanyo GA or Samsung 35E. You can also just use the classic 30Q or any similar cell.