The ground is literally a stones throw from the Piazza dei Miracoli, so good, cheap bars will be hard to find. Your best bet will be to try the area to the north of the ground.
There is a very good restaurant in via Santa Maria, almost at the foot of the Tower, I think the name is Antonietta, well worth checking out. Reasonably priced for the location and very good quality.
We saw the ground from the top of the tower this summer - if you are situated in the right part of the ground the view will be fantastic even if the football isn't.
