Are you familiar with Freespirit Publishing?
Take a look at:
http://www.freespirit.com/catalog/catalog_detail.cfm?cat_id=29&show_all=true

A book like this one might help a lot:
1001 Great Ideas for Teaching & Raising Children with Autism or Asperger�s
$24.95
Ellen Notbolm and Veronica Zysk

So I would try to educate the GT, but I would also look for others associated with the school as potential mentors for your son. Is there someone in charge of IT who would be willing to do an 'independent study' with your son? Or a Math teacher? What is the Media Specialist like?

Are there alternatives to the current school? Can you homeschool, or homeschool part time?

Best Wishes,
Grinity

Coaching available, at SchoolSuccessSolutions.com