My older dd's WISC profile looked almost exactly like that at age 7 but she does not have Asperger's or ADD, so she presents pretty differently. I'd approach this primarily viewing the Asperger's and attention problems as the issue not the processing speed. A child with avg processing speed (my dd's was actually a bit lower) can do well in a gifted program with no other complications, but your ds has other complications.
My dd has been given accommodations for extra time as needed but, beyond that, she's not needed any help and she is both grade accelerated and in advanced courses. We don't have any fully encapsulated gifted classes like you do. Does he have an IEP or 504?
