Just a clarification... if the priest's wife dies, he may become a bishop, at least in the Russian Orthodox Church. When I was growing up, a neighbor of mine was the legitimate daughter of a Russian Orthodox Archbishop.
By the way, I've heard it said that although St. Peter was at one time married, there is nothing to show that his wife was still alive at the time he became a disciple. The argument is based on the incident when Christ healed St. Peter's mother-in-law, she rose up from her bed and waited on them. If his wife had still been alive, she would have been the one to serve them.