I know Ison’s and Bottoms Nursery will ship in the fall. They are mostly known for other things (Isons for muscadines and Bottoms for blueberries) but they also have fruit trees, not many, but some, and they are mostly popular varieties. Only thing is they do not list the rootstocks. Isons did reply to an email inquiry when I asked about the rootstock, though, so you should be able to get that info on request from them. Bottoms Nursery, I don’t know.
Isons is pretty highly rated, and I’ve personally ordered from Bottoms (blueberries and a fig tree). I thought their packing was a little careless, (resulted in a few broken blueberry branches) but the things they sent were healthy and their prices and shipping were pretty cheap, especially since the things I purchased were potted and not bare-root.
You might also call Cummins Nursery. I know there are some trees that they are willing to send out in the fall, even though they apparently don’t put that info on their website.
I also know Raintree will send some things in the fall, and those are listed on their website.
Century Farm orchards ships starting in November. They mostly deal with heirlooms and Southern apples, but they also have some more modern varieties (Fuji, Gala, Delicious, Granny Smith, Goldrush, Enterprise, McIntosh, Pink Lady, Liberty, Florina, Rome, and a few more.)
I’m sure there are others, but those are the ones I can think of off the top of my head.