Next headmaster at Hogwarts? HP fans.?

I'm writing some Harry Potter fan fiction and can't decide who to make the headmaster of Hogwarts. My story takes place 13 years after the final battle of Hogwarts, making it present time. I was thinking about choosing Firenze the centaur, to show how the wizarding world unified after Voldemort was defeated and started to think of everyone as equals. It can't be Harry, Hermoine, or Ron because they're off doing other things. Mcgonagall was headmistress when filling in after Dumbledore's death but she retired. What about Professor Sprout? Any suggestions? And please take my question seriously.