Ant, I would think that life as an instructor in SV would be pretty good. They have some of the best groomed, high-speed cruisers anywhere and SV/Ketchum is a fantastic little community.
Snowbird's great, of course, but I bet you'd make a lot more money (aren't I crass?
: ) at Sun Valley.
Also, it's not like you're choosing between Toledo and Paris. Sun Valley or Snowbird would each be great in its own way.