This breaks with the established clip format, but I say play a great Punch You In The Eye all the way through. It distills all the pieces that make Phish great in one relatively tight tune: you get some storytelling (without needing to know the history, college thesis blah blah), a great dark chord progression, Latin jamming during the Landlady section, and at the conclusion Scott will either start to get it or he won't.
Since Scott mentions liking jazz, I'd lean heavily on that & play him the early fugal compositions. You were on the right track with Fluffhead, but that's *way* too inside. Try Guelah Papyrus > Asse Festival, the jam from Dinner & A Movie, and how about Buried Alive?
I'm also shocked you didn't play Foam right out of the gates!