It's easy to make your own. If you want a cure for something like summer
sausage, I use Morton's Tender Quick. You can also get pink salt which I think is the same thing.
For jerky I have marinated in a soy sauce mixture, with lots of black pepper.
For jerky, you need to slice the meat--non-fat like top round or such because fat doesn't do well in jerky. Chuck is too fatty--unless you are using it for grinding. Slice and then marinate, then dry in a very very low oven on grates.