Disease and insect free varieties of Fruit trees

Are there any other interesting fruits that can grow in zone 7b (North Alabama)?  I am looking for ideas on the "Other than normal" ground covers, vines, bushes or trees for the Southeast USA?  Very Hot and Humid summers here but I have drip irrigation almost everywhere.
I am enjoying trees like Asian Persimmon and Jujube that seem to be relatively free of problems.  I find that using Compost tea helps prevent Fire Blight on my Asian Pears and I recently planted Chinese Che and will soon plant Schisandra Vine.  
I have a shade cloth covered Pergola that I can plant between the Kiwi.  The soil is pretty neutral 6.5 to 6.8 pH.

Thanks

Best resource I have seen, read and heed!

This tracks almost perfectly with my experience. Solid human beings, this is an absolute wealth of information. I look back on this regularly, it is that dense with useful stuff.

Tj - A very enjoyable read and I now have some new ideas.  Thanks, I am now thinking of Pomegranates since I have almost all the others except pecans and filberts. I would like filberts but only if I can find a way to unshell the fruit mechanically. Otherwise I will be stuck with buckets full of squirrel food.  Picking is one thing but cracking nuts is another.
I now have a shade cloth pergola and may try currrants.
At the very end there is mention of citrus that may be compatible with my area. Outside of the Trifoliate Orange I did not know any citrus would survive up here.
Some wonderful ideas and a great resource material. Thanks