The Boppy is a must have. You will use it for feedings and to prop the baby up. If you have multiple floors, it might be nice to have one for each floor, so register for two. And be sure to register for at least one cover as they get dirty very easily.
Most of our nursing Mama’s used My Breast Friend, a firmer pillow (as opposed to the Boppy), when breast feading. It straps around your mid section so you don’t need to use a hand to hold it in place.