I wouldn't try to emulate something non-kosher, or at least something that is pork based, you won't be able to.I've made
kosher sausages in the past using beef shoulder and fat and it worked out pretty well. As for casings I used Devro, but you need to buy them in bulk. I was intrigued by a story today in Tablet
in which they reference kosher lamb intestines available for sale in France . Was planning on trying to source them, if anyone's got any insight I'd be grateful.