There are a lot of recipes out there for homemade sausages. I make my own but usually have patties because I don't want to spend the time stuffing links.
It's basically ground pork (mince) with various spices to make the type of sausage you want. By making your own you won't run into rusk or dextrose or starches in them...and you can have them NOW.
Linda Sue has a ton of low carb recipes. Here is her recipe for
hot Italian sausage to give you an idea. As U.S. breakfast sausages taste different from bangers, a Google search on them would give you an idea what spices to use. HTH