I have a real good natural foods grocery store locally with a great butcher shop. They stock casings, seasoning mixes, sawdust, twine, burger bags, hog rings, various cures. If I can't get what I need there, I go through Sausage Maker, or www.alliedkenco.com
, or www.lemproducts.com
. I have other online sources I've visited, but not ordered from yet as well. These listed should get you in as much trouble as the rest of us.