Here's a link to a list of plants native to Alabama.

http://www.wildflower.org/collections/collection.php?collection=AL

The Carolina allspice sounds nice.

Japanese garden juniper does well as a low growing 'ground cover' type evergreen & would look great around around a rock garden. You can trim back the running branches when it eventually gets larger. It would do well to keep your existing soil under control and then plant your perennials in and among some small beds until they get established. I have some around my pond that trail over the stacked stone wall. I keep it in check now by pruning and can walk all over it to get to other things around the pond as needed.

Ornamental grasses are good for slopes. They put down deep roots that help stabilize the slope. Some attractive large rocks or concrete pieces can help hold things together till the grass takes hold. There are grasses in all sizes and forms, so you should be able to find some that suit your needs. Let us know what you decide to do.