I think you need to revisit Colorado for the sheer number of possibilities and rentals that would be available. And the ease and probable cost of getting there from your two areas of departure.

Don't know if I'm too late but here's my 2 cents. Have you looked into the Canyons in Park City? I've gone out to Park City the last 5 winters to ski, and we don't even bother with Park City Mountain anymore. The Canyons is huge, much much less crowded, and is great for a variety of levels. This year my extended family came with, and everyone from my beginning snowboard cousins to my double black ski racer brother was happy. I'm in my 20s and had a great time at the bars on Main Street in downtown Park City. It definitely doesn't feel like Utah there!