I can't comment specifically about your son's disability but in our pack we have a boy who has Down's syndrome and we have him in our regular dens and he does fine. We do expect that the parents help us understand how to best work with him.
If your son would join our pack, I would welcome him and work with you on what he can and can't do. The other boys might learn something from your son. There may be some things he just can't do but usually you can incorporate the boys into something at the same time. In general, I think only sports games might be an issue. Everything else would be fine, IMHO.