Comprehension is not a supplemental test on the WISC IV - it is part of the standard battery of tests - I don't think they can even caluculate a FSIQ without it. So, they must have just left it off accidentally on the scores they gave you.

My DS's scores are similar to yours. He was tested on the WISC at 7.5 but prior to that he was grade accelerated and now attends a HG school within a school program. Point is your DS will need something different.

Who did the testing? Was it accompanied by achievement testing? Maybe with that you could apply to DYS (Davidson Young Scholars) How is your DS doing at his current school? Do you think they would be willing to accomodate him either with grade or subject acceleration?