On germinating pawpaw seeds, I planted 14 seeds outside in pots, way later than I would have liked (I forgot them through most of the summer, "chilling" in the fridge). I planted them in late July, and when I returned from a 2-week trip on August 28th, at least 8 had sprouted visibly. They're 2-4" tall on average-- my first pawpaw sprouts! This is in SW Pennsylvania.
For any pawpaw fans in the area, Plumline nursery outside Pittsburgh currently has some Peterson pawpaws. They're pricey but quite nice and full, about 3 feet tall. I bought some earlier this summer. I haven't found any others in this area.