I discovered St. Lawrence Nursery a few years ago... they specialize in fruit trees for northern climates. I just skimmed their list and don't find either sold through their site, but maybe I missed it? (didn't see a search feature). I'd suggest you look at their site: http://www.sln.potsdam.ny.us/

Here in WNY pawpaws produce edible fruit. Delicious! In fact there are wild pawpaws growing along a creek about two miles from my house.

We have two persimmon trees which produce plenty of fruit but they never get ripe enough eat. There is nothing more sour than an unripe persimmon.

Pawpaws are actually native to this area of the country, so they grow really well. They are wonderful trees and I wish I had enough room at my current house to grow them, but they only come in standard size (up to 40'tall) and you need 2 for pollination. If you can spare the room though, I would definitely recommend them!

There is a nursery in Canandaigua, NY called Millers. We love them, and I think they actually have 3 varieties of pawpaws.