I've had good success with Lem's and The Sausage Maker (TSM) natural castings.
For a while now I buy tubed hanks. They come on these big plastic straw like things that make it easy to put on the stuffing tube.
When I do the processing from my yearly hunt it is often just me and when I'm lucky 1 other person so every minute of time is precious to get it all done ASAP. These tubed casings speed things up and are the way for me to go. No fighting with getting casings on a tube when stuffing 200+ pounds of sausage in a few hours.
I follow the
boykjo
practices of soaking for a week before using and changing the water out as I go.
The tubed casings don't come submerged in brine BUT come salted and wet like they were pulled from a brine and then had salt slapped on them for packaging and shipping since they aren't shipped in the liquid.
Also I really like the cellulose/plastic casings these days for making skinless dogs because they are so freaking easy to work with and so fast to work with. The only issue with them is that you gotta commit to smoking them. There's no cutting raw stuffed links and vac sealing to freeze then cook/smoke at a later date.
Finally, I don't care for fighting with lamb casings anymore. They make an amazing smaller sausage but the fight with them and the time it takes to mess with them and the ease at which they break or bust is not something I want to deal with anymore. I LOVE the cellulose/plastic casings for skinnless dogs in the same diameter for making pork franks (hot dogs) and sausage of that size.
I hope this info gives you some more ideas :)