Try www.isons.com; they have a good selection of varieties for southern orchards.

Petals from the Past in Jemison sells 'Kiowa' blackberry bushes, a picture of which can be viewed on the link below, or on their website at petalsfromthepast.com. It's supposed to be the "Cadillac" of blackberries.

Just noticed you're a new member, so "Welcome!" to the Alabama Forum, and best of luck with your search!

Nelson

Here is a link that might be useful: Kiowa Blackberry Picture & Info

Southern Homes and Gardens in Montgomery usually carries blackberry plants throughout the year although they are somewhat pricey. I think a 1-gallon plant will run you between $12 and $15. Any of the blackberries with Indian names seem to do well in Alabama.

Simmons Berry Farm is a good mail-order source.
I'll second the nomination for Kiowa - heavy production of huge berries with good flavor, but let me warn you, it's one THORNY sucker!