From what I understand, they don't stock them in their stores, but they do stock them in their numerous warehouses(per one of my friends who worked in the walmart hub). You have to order them via the internet or a special order from the store, they will then query the warehouse that has your model and have it shipped directly to the funeral coordinator/home you are using. They usually ship same day and always within 24 hrs and are received on the 2nd day after ordered.
Their Supplier is Star-Legacy, They state all metal caskets are made in USA, and all wood models in Canada.