WLH,
I never grew any plums back home in east-central AL; just relied on the native Chickasaw types. But, my understanding is that some of the AU (my alma mater, WarDamnEagle!) selections are pretty good - and they were bred in your neck of the woods.
I've tried a number of plums, as well as some pluots, apriums, and peacotums here - all were a bust. But, the 'Guthrie' selection of P.angustifolium is a winner here - and the fruits have a peach-like flavor. If you like that sort of thing.

Here is a link that might be useful: Southern Plums @ JF&E

Spring Satin is supposed to be a good plumcot for the SE. I just put one in this winter. It was developed in Byron, Ga and is supposed to have good disease resistance. Reviews I've read on its flavor have also been good. You can also search GW as there are lots of threads about it. Additional info below.

Here is a link that might be useful: Spring Satin

I have Gafford pecan scion wood and want Spring Satin bud wood. I do not know how to use this new houzz message board to send you a message. Help.

I looked in support. Apparently you must enable other users to message you. I made sure mine is. John 850-twotwo8-six099. My spring satin are budding out here in North Florida and we're dipping into the low 20's tonight

I have Flavor Grenade, Flavor Queen, Flavor Rich & Spring Satin and they all do well for me. I'm in SC. If you want any of the AU series of plums, the best one is Rubrum.

Rayrose, Thanks , I think I have a comment from Florida. Bill