I am not sure paw paw trees would do well as far north as Bradford, PA... I have only found them growing in the wild in far southern PA. But if you have the cash to take a risk, go for it...
I have several planted on our hunting property in southern Bedford County, near the MD line. They have done well, with them all being in excess of 15 feet and producing fruit.
We purchased our trees from
http://www.ediblelandscaping.com/ We got 5 'Davis' cultivars, 5 'Mango' cultivars and 5 straight wild paw paws. All have done well, but the Davis and Mango do seem to produce more and larger fruit. The deer do not browse the leaves and don't appear to eat the fruit. However the bears, coons, possums and squirrels seem to fight tooth and nail for them. I love the fruit as well. Tastes like a banana custard. VERY GOOD!