...depending on your taste, of course.
Whether it be fatback or bacon. I prefer to use jowl fat when it's available. If you just used bacon as your base it would be unpleasantly fatty and difficult to cook.
And is sucked. I couldn't believe it.
would be to cook the bacon most if not all of the way, break it into bits, then add that to the uncooked pork sausage mix. You could even cook it in the bacon fat (as if pork sausage is so lean it needs more fat to cook). A big part of bacon is the texture. Simply grinding it and adding it to other ground meat in a uniform mixture would dilute what is good about bacon.
you're halfway there
Bacon Sausage™ brought to you by Fischer Maxtronics
it might be gettin phased out though