The Cessna 206 with conventional gear is the primo bush plane, so don't discount tricycle gear either. In a SHTF world, there will be plenty of roadway available between road blocks and etc. I expect GA (general aviation) to play a very important roll in transporting people, supplies and medicine as is the case in remote areas of the world where there isn't any roads. That is, unless some damn oppressive dictator like Obama comes to power and implements a no-fly zone over the U.S.
Check out this site for what's available and current prices: www.aso.com
I don’t fly, but I recognize the value of GA post-collapse. In fact, I’ve incorporated light planes flying off roads and dirt strips in all of my four novels as critical plot elements.