I'll second the recommendation for Scenic Mountain Air in Moose Pass, AK. But, it's not a rating mill. These guys work in flying back country Alaska and you'll get a comprehensive sea plane and mountain flying course combined. They fly Super Cubs that are very well maintained onsite and Vern Kingsford, who owns the school and is the DE for your checkride, runs a tight ship there. It was one of the best vacation, learning experiences I've ever taken. We managed to get in some serious fly fishing in the world class Kenai tributaries while there and saw moose, bears, eagles, sheep/goats, caribou, ,.... There were a fair number of airline guys passing through for repeat trips there as well.