Male or female catfriend?....that eternal question! I think it really depends on the personality of the kitten. To me your guy sounds quite dominant, so 2 dominant males may result in rough play escalating to fights. I currently have a male and female. Female is slightly older and more dominant, and male kowtows to her most of the time, but when he grew bigger and stronger then he tried to dominate her. Things have never really gotten out of hand and they've never had a real cat fight. Most of the time they play chase games and they're cuddle buddies and groom each other, but every once in a while my boy tries to topple the queen from her throne. If the female is tortie or calico, they can be pretty bossy and usually end up being the alpha cat. Maybe try "flip on back test" on the kittens. Turn upside down and see which one wiggles and doesn't like it or one that accepts that position for a little while. Wiggler will most likely be the dominant one of the two. I would go with a more dominant female, than a dominant male. A kitty 14+ weeks old should be able to deal with Logan---12 wks. might be a bit young. Good luck!
"We humans are indeed fortunate if we happen to be chosen to be owned by a cat." -- Anonymous