I would certianly take a look at the special needs school, but I wouldn't jump to move him out of the gifted class.
Is the gifted class full-time? What criteria does the school use to place a child in this particular program. There may well be a LOG (level of giftedness) issue causing him stress.
Is the person who did the testing availible to make any suggestions? Has the school provided 'friendship groups?'
What provisions are in place so your son can take a break appropriately when 'it' gets to be too much?
Are there any triggers that can be noticed and managed?
Do you think he's bored in school and that is triggering the unwanted behaviors?
I would certianly get that Davidson YSP application cranking if you haven't already. He is certianly highly gifted, profoundly gifted by my definition. And his processing speed is probably enough slower than the rest of him that it creates some tension, unless it is an artifact of the testing situation, or perfectionism.
Does your son have an IEP? or 504? what's in it?
What does your son say about when he disrupts class? Does he like school?
What is your son like at home? My son is high in WM, although not as high as your, and I've learned through experience that he can track an argument much better than I can!
I'm so glad that you are here!
Love and More Love,
Grinity