My bad I didn't see these replies until today.
First regarding the altitude, recently talked to a friend of mine who said it didn't really bother him there, and granted he's from OH as well. I've also read that Ginko Beloba (although not proven) possibly helps.
Regarding the flights. Durango is cheaper by almost 100 bucks. The only problem with that is the shuttle (Telluride Express) that runs to Telluride has a 4 adult minimum, so as it stands with my buddy and myself it wouldn't really save any cash.
The price to fly into Montrose vs Telluride airport is about the same (on weekdays about $550 from cheapoair), but I've heard that the Telluride airport is more prone to delays and cancellations due to storms. The 2 hotels I've been looking at in Telluride both say that there's no one at the check-in office after 5 or 6, so a delay could really screw things up.