Elle has a great list of different fruit trees and specific varieties in this thread
Fruit trees and berries that grow best in your area naturally- Continental climate hardiness zone 5
I personally like smaller trees better, because they usually adapt quicker to their new environment and grow quicker as a result than if a large tree is planted. If you buy good quality trees, they should produce by 3-4 at the latest for most fruit trees and some nut trees, but nuts could be closer to 7 years for some types.
It's best if you can put them straight in the ground, but you could definitely pot them if you have to, but the sooner you can get them in their permanent home the better.
Hope that helps, and happy planting!
