Pork is great... I cleared out the grocery store when they sold pork picnic shoulder for $1.19/lb. 8lbs of pork shoulder gives about 7lbs of meat and 1 pound of bone. The bone I throw to the dogs for a chew toy. I don't know if your grinder can handle it. I like pork (from the grocery) because it's not "bloody". Beef can get pretty bloody after chopping it up so it's a mess to clean. I don't grind though, so I only have to clean the table, the chopping block, and the knife.

Pork necks are cheap too and the grinder can probably crunch through the neck bones.