Did you share the WIAT results with the school?
Have you checked your state laws on gifted education? Have you looked into part-time homeschooling (more than one day a week)?
Homeschooling him in math until you can get a program in place for him at school would be one option (it sounds as though you are doing this at least one day a week). In my experience, advocacy can take time (and there is no guarantee that the school will be flexible enough to meet your DS's needs). Your DS needs a school that is flexible.
We found IXL to be a bit slow for our DC - there is nothing wrong with it necessarily, but at a minimum, your DS probably needs to work above-grade (and possibly several grades up). EPGY has changed - DD used it before it changed to Redbird, but they kind of lost her during the transition with too many frustrating glitches. I am not sure if Redbird is still really geared towards gifted students, as some of the marketing looked as though it might be moving away from that (and we have moved on since then). Perhaps someone here is using Redbird and can comment.
I have a VERY similar situation with DS. I've also been though shades of the same with older DD...and she DOES check out.
How old is your DS?
