16SF is a non issue. I don't even know why that model exists. A double hilt 16 does the job just fine and doesn't look cobbled together. The finger relief cut on a 16SF is about useless. You won't want to use the knife in the upside down mode with those finger grips digging into your palm, so what is what is the point?

14 is a big knife and as a fighter will do it well. It also offers the greater utilitarian use over a model 1

I think the obvious choice here as a fighter only is the model 1.

I will say, as a pure fighter, the model 2 reigns supreme. That is the sole purpose for its existence.