Check out largefeet.com. My son wears a size 15 and this store is great. It is in downtown Atlanta and they carry athletic shoes size 14 and up. Shaq gets his size 22s there. my son loves having a place where he can try shoes on. ��
I am not sure if they have molded cleats in stock. But if you have a free day, it will be worth the drive. (It is not an impressive store front and you have to walk up to the third floor for the athletic shoes. But they have a great selection.