Source for different Chickasaw Plum varieties

I would like to add some native plums to my collection and hear good things about the Chickasaw Plums.  Does anyone know where to get the different varieties (hybrids) that other groups are talking about?  I am looking for some that can do well in North Alabama and since we tend to get late frosts I hope to find varieties with different bloom times.  

Overhill gardens , east tn

They do carry the Chickasaw Plum but I am hoping to find some of the new varieties.  May have to buy scion wood and make my own in the comming years.  
Thanks for this nursery.  They carry a lot of interesting plants/trees.