It shouldn't hinder him in terms of getting a job. My only concern would be how his Asperger manifests itself and how he controls it as schools are stressful places and education is a minefield. I've got several pupils with Aspergers and ea h one is different in their own way, but I love teaching them. I've made a real break through with one and his ability to understand sarcasm and not taken too many things literally.
I know he wants to come over and teach in the States at some point. Not sure he'd get in with his C connections, but it might be a very good route. The accent and how he is would certainly have the kids more engaged I think. Some will take the piss (I get it every day), but I can see him forming a good connection here.
My nephew has aspergus, he looks like Sheldon Cooper, but taller. He's 13 and 6ft 6", he's going to an engineering school which suits his interests and capabilities perfectly. I love how he's a walking encyclopedia. My step son is ADHD, totally hates school, should do a ton better, but once he's out of its confines, he'll probably do very well if he channels himself properly.