By Zach Barnett This is going to be a long, long season for a certain set of NFL head coaches. This is going to be a long, long season for a certain set of NFL head coaches. With four months still until Week 1 of an 18-week season, we have another report linking Sean Payton to an NFL team. This one’s from Front Office Sports, who writes that the Panthers are eyeing their longtime NFC South rival if Matt Rhule does not guide the team to the playoffs in his third season on the job. View the original article to see embedded media. That reports adds Carolina to Dallas and Miami on the list of team…