sorry, but.... which Kyogre please?

B

Either one would be a good candidate to take to max. Kyogre A will have a higher max CP, and since it's base defense is already high (250) losing out on two points won't make any difference.
That said, fun fact! The difference between a 13 stamina Kyogre and a 15 stamina Kyogre is 1 hitpoint. In fact, at lvl 40, your 13 stamina Kyogre will have the exact same HP as a 14 stamina Kyogre (154).

So again, either or is a good option, so I'd probably go with option A simply because it's CP will be higher.

A is the way to go! It has higher CP and less defense means, you gain energy faster which can be the difference between getting of another HP.

yes and by higher CP they mean 4059(A) as opposed to 4054(B), really you can go either way the difference is too small to "feel"

I had the same dilemna
15 15 12 (Attack Defense Stamina) or
15 12 15

On pokebattler against Groudon, they yield about the same results.
I picked the first one, but now wish I had chosen the second one. Why? Only because of the final max CP! My 15 15 12 tops at 4043, while the 15 12 15 clears 4050. Too late now!

2316 hands down
Just 1 ps less than the other and 2 more defensive potential breakpoint

why choose ? do both