Google say MS Extension service or your state colleges or universities. One or more of them will likely have suggested varieties for MS listed. If you dont have native plums you probably dont have the best conditions for growing them. Plums tend to be susceptible to rots and spots.
I have quite a few chickasaw plums on my place, but I didn't plant any of them. I suppose the wildlife did for me. They grow six feet tall or so and, when I can miss a late frost, put out tons of plums in the middle of June.