Jeffery Hildebrand would be my best choice as he is closer (Houston), on the younger side of the list, made his fortune in oil, and is a big contributor to Catholic Charities. I see a pretty decent synergy there for wanting to keep the team in new Orleans, and as being someone Benson wouldn't mind selling to.
Dan Friedkin may be a good option too. He has business dealings in Louisiana, so there could be a desire to stay loyal to the area.
But I have a decent confidence that Benson has a solid succession plan in place going forward. He isn't a billionaire by accident. He always had a plan "B" of sorts if the three R's broke bad.