Thanks for the info Peony and Pattimomma. I will be looking up the links you provided Pattimomma, and seeing if any would be helpful for ds's situation.
I am planning on signing both my kids up for a summer program through the school, but it is not extended school year. It is specialized classes in various topics of interest that are not covered in the regular school year. Ds wants to take the classes on mindstorms (Lego) and young entrepreneurs. Dd wants to take Ancient Egypt and a poetry writing class or chess. The kids are looking forward to it!