Allegri is the only one that I'd feel confident is able to build on what we have while winning. If I were him, I wouldn't be leaving Juventus at this time though, 2/3 years from now maybe.
Pochettino probably would increase the prettiness of our football, I'm not sure about his ability to win anything. Spurs is currently a better side or as good a side as we are and they are not really going anywhere.
Zidane is a 3× CL winner and a La Liga winner yet I feel than he's still a relatively untried manager. I'm not confident of what he could do with this team. Maybe after we've finished building a proper team/squad.
There are many options and reasons for and against. I don't envy the board having to make a choice. It will depend on what they are looking for...trophies, youth, consistency etc.