I need to order a backup/out&about mod to use (currently use a Provari Mini). I want something small and short (not long like the 10440). I can't decide between the P+ 16340 or the P+ 18350. I'll be using it with a small tank, and I already have 18350 batteries, but if it's much shorter I wouldn't mind springing for some 16340 batts. If anyone has both and can take some comparison pics, that would be a great help. If you also have a Provari Mini and either of the above, some comparison pics of them together would be even better. Thanks much in advance!