I've learned from some of the men on this forum and 2 others that a gentle sloping southern exposure is a good place to plant fruit trees. Keep them up higher on the slope so they don't sit in a low frost pocket. Up higher, you get more breeze, less frost AND disease probs.
My camp is in northern Pa. and we've planted Enterprise, Liberty, Goldrush, Wolf River, Prairie Spy, N.Y. 35 Bonkers apples, as well as Dolgo, Chestnut, Whitney, Centennial, Hyslop, Trailman, All - Winter - Hangover, Centurion, Nova Scotia grafted crabs. We also have a few un-named crabs. All are doing well and have not shown any real disease probs. so far. Other than spraying for insects, they have been pretty easy to care for. The rootstocks we use for the grafted ones are B-118, MM-111, and Antonovka. Our best trees so far ( growth-wise ) are Enterprise on B-118 & MM-111, Liberty & Wolf River on Antonovka, N.Y. 35 on B-118. Dolgo, All-Winter-Hangover, Trailman crabs on Antonovka.
MNFISH, in post #22 above, mentioned planting lots of crabapples. We have had GREAT luck with crabs. I don't think you can go wrong with them - and - they are good pollinators for apple trees.