You can try Hoover & Strong for mill goods but they can be kinda funny about who they will sell to. You have to call them to find out if they will sell to you. They don't want to sell to anyone who will compete with their primary customers, jewelers. Rio Grande is another option. They apparently sell to any one. Generally, sterling is all that is available in silver and I would think that would be good enough. If anybody could provide you with fine silver, that would be Hoover & Strong as they are refiners.