If you want to incorporate a couple of my family's favorites...toss in some country ribs, they add great flavor. My grandmother actually used fresh pork hocks and I loved them but the country style ribs suit most people better. Another thing she always added to the sauce was hard boiled eggs. They don't add flavor to the sauce, but the eggs do pick up flavor from the sauce (& kids love them).
My grandmother was straight off the boat from Sicily and I think she added those ingredients because they were readily available and cheap. I also frequently add sauage to my sauce.