It looks like you're looking to subject-accelerate in math? I think you have what you need already without further testing, just need to figure out how to "package" and present it when you talk to your ds' school. When we advocated to subject accelerate our ds in math, this is what we used:
1) IQ/ability score - it sounds like you have your full WJ-III report - look for a number called the "GIA" - that's your ds' IQ according to the WJ-III. Since he had a lot of "Very Superiors" I'm guessing his GIA is at a minimum above the 98th percentile, which is unarguably a gifted IQ.
2) Math achievement scores - your ds has tremendous scores! No worries there
If he's had any state testing yet or other in-school testing where he has high scores, you can use them too ... but... you shouldn't need to with the WJ-III scores he has.
3) Proof of math ability through work ds had done at home - I don't think you should need this, but if you do, try to tie examples of what he's capable of to state standards or your district's curriculum standards at the grade level (or above) that you're trying to accelerate him to. You might not have to do this step but we had an ornery school we were dealing with!
Good luck!
polarbear
