Yeah nothing wrong with having a few choices in smaller lights 
Maybe the Keeppower 18350 protected would be better for you but I’m not sure about it fitting lengthwise.
The Keeppower 16340 should be ok though with non high discharge cells they will wear out a lot faster in this light.
The EC11 can pull about 4.5A if I remember right but it’s a real pain the driver not having low voltage protection, I can understand you wanting a protected battery.
I would recommend just using a proper high discharge cell like the Aspire 18350 and get into the habit of checking your cells regularly. It will also release the full potential hand warming function of the light :laughing:
I would stay away from Olight, Nitecore, Jetbeam and **Fire cells, there are better alternatives.