OMG that horse is an absolute doll. I for one LOVE a horse that is interested in me and seeks out interaction. Been around too many lesson horses that just couldn't care less about you. It's sad, really.
While there is risk in getting a horse that you haven't ridden, you've clearly assessed that risk and have a plan either way. But the right temperament is so important and I think you can tell a lot about a horse from its ground manners. It's possible the horse knows you, but it's also possible it just likes people. Our horse is like that. After 6 months, I can safely say he knows me (he comes to the gate when he sees me, we have "rituals"), but I think he'd be interested in anyone because that's his nature. Sometimes I think he likes people more than other horses.
Please give us updates and tell us all about your experiences!