I would call them highly gifted, yes. (My DS is right there in the same GAI range but with more even scores).
That said, I don't know that talking to schools directly about levels of giftedness is going to get you anywhere. You're better off discussing needs of your individual kiddos and keeping them engaged. The scores are rare enough that they should speak for themselves (I know they startled our gifted coordinator when we first met with her). The WISC is pretty well known do it probably doesn't need interpretation on your part to signal that your kids may have some extraordinary needs.
