I'm pretty sure all Messor species are european. As for its closests American cousins ( I.e, species in the Stenammini ), there's Stenamma, Aphaenogaster, Novomessor and Veromessor which I heard are ants for keepers which kept a colony or two successfully. As for keeping Messor, the only two things that can be annoying with them ( at least from hear-say as didn't have the pleasure, or will ever have, of keeping Messor ), that they're very sensitive to vibrations during founding stage, often eating brood, and that they can't be kept in nests from plaster or Ytong as their majors can chew through it.
By related species I meant pogonomyrmex, they're also harvester ants. But thanks for the tips!
I'm not in the US though, I'm in Russia so there's no problem with messors
Also I read some posts about messor and veromessor having relatively dumb behavior, if that's true though