1st choice: Ibiki (he'd likely be intrigued with the thought of interrogating a book)
2nd choice: Iruka (who better to oversea a conversation with a self-proclaimed 'student')
3rd choice: Anko (It would indeed be fun, and she has experience with snake bastards)

Least favorites (tie)

Tsunade: ditch paperwork to watch someone write? not when there's quality nap-time to catch up on.
Team Gai: Power of Youth speeches have no place in this.