10 poles will be the lowest cogging, for the highest copper efficiency, (intrinsically due to the LCM of the slot/magnet numbers, higher is better), the connections are complicated but the coils are the same as 12 poles.
I would not go any higher than 12 poles because iron loss at the higher pole counts is pretty high, and its not until you get to 26 poles or higher before the fundamental winding factor rises back up to acceptable levels.*
14 poles has an LCM of 252, less cogging than 10 poles at 180, but the fundamental winding factor is .55.. which means you get 55% of the voltage (60% of the 10 pole number) 16 has an lcm of 144, and about the same winding factor.
unfortunately you have to take the fundamental winding factor and square it, take the reciprocal of that to find copper losses.
*As far as acceptable winding factor, that depends on how much power you have. it may be appropriate to use 14 poles (the worst option, but least cogging, except for 26 poles) if you only expect to get 50 watts out of it. but if iron loss dominates at 14 poles at the rpm you expect, then 10 poles would be better.