Since your climate is so different, I can't advise you on the when. I'm sure it's earlier than my zone 5b area. Check out doubleavineyards.com. They have MANY varieties, and you can sort them by type (table, wine) and also by agricultural zone. The descriptions are helpful; one tab at the bottom lists disease susceptibility, though some just say "unknown." I have no idea what diseases might be lurking in my area, so this will be a big experiment. The only grapes I know that do well are my neighbors, and she's going to give me some cuttings. Oh, and wild grapes, they're all over. But they have tiny, seedy little fruit.
Ah! What happened?
I got some Magic Molly purple fingerlings from MPL, and they did MUCH better than the purple variety I ordered from somewhere else. The MM potatoes are small-medium, for the most part, but they are fingerlings. I have enough of the 3 kinds I planted left that I won't need to order any kind of seed potatoes this year.