Hey, LMom,
Haven't had the time to follow up on HeyMath! I emailed them and they asked me to call them to discuss it, but they also have an advanced math course. Can't recall, but look on the site. It was something like PM or PEM.
The Destination Math is perfect for DS8 - visual and fun. He does best with work that doesn't look like work. Your DS might like the EPGY courses - you can check them either on the CTY site or the EPGY site. I think the EPGY site has actual demos you can see. The course was fine - but too dry for a visual-spatial type learner. If he didn't object so much to it, I would have continued b/c that way I'd know where he was on the progression.
