T.T.
I'm so happy to see that you are getting him evaluated at your ISD. If they can't help you, I bet they can steer you in the right direction!! My older son has problems, but didn't qualify for the ISD program. We have been getting him therapy through Our Children's House Baylor. Therapy has done wonders for him.
I wish I could help you with a school. I know there are some around that specialize in "special needs" children, but I'm not sure were they are. Try the Dallas Child magazine and other local parent resourses. I bet if you call around someone can get your there.
Good luck to you, and if I come accross anything I'll let you know.