Agree with Charlie. But also, it's pretty much a meal in itself, so you don't really need
anything with it (except the "lots of wine," preferably a Chianti).
Note that in Italy panzanella is often an antipasto these days, preceding a lightish summer meal. In the old days it was a main meal to use up stale bread, which is the way I still prefer it, loaded with ripe tomatoes, anchovies, olives, roasted peppers, capers, olives ...