I live in Pa and I would recommend staying in southern Pa. The Ohiopyle area has a large waterfall and scenic overlooks that are quite nice. Near Ohiopyle is Frank Lloyd Wright's Fallingwater and Kentucky Knob. Also Ohioplye has world class white water rafting (many raft companies) as well as hiking and trout fishing. You are about an hour away from Shanksville - Flight 93 memorial.
You are close enough to Pittsburgh to see it's attractions on a day trip or 2. You could also split the trip and stay a few nights in the Gettysburg area. Close to Amish country too.