have you read Natasha Campbell MacBride's book.
also, Marilyn Le Breton's books (both of them - Diet, Intervention and Autism, and the AiA cookbook) have soe info.
Have you thought about enzymes? especially as you said on your other post that you thought gf might have helped but you cant get ds1 to stick to it. enzymes could help him with the digestion of the gluten. Karen de Felice is your woman there - good book, lots of info. som info on website too.
will have a quick dig around and see if i can come up with some links.