Sorry, I don't know if I can predict how they would fit you.
For me, the 14s and the 12s aren't *that* different; just that the 12s required a little longer break-in period to feel good and they stayed a bit tighter once broken in.
If I compared it to US shoe sizes, the two would be like a .5 size difference.
The difference between the 14s and the 16s is much more noticeable for me; like a full size difference.
My first pair of Boons back in 2009 were 16s and very big inside; my current pair is not as big, but when I think of Boon 16s, I still think huge hand pocket.
I'm almost scared to use my current 16s because I don't want them to stretch out; but at least with knuckle guards, they should still be good even if that happens.