Why not do some covers that are not expected. So cancel out all Popular Jam Bands and the famous classis rock bands like Zep, Floyd, Beatles and such.
Goblin - a cool instrumental band that has done the soundtrack for basically all of the Dario Argento films.
The Band - I can see Jordan singing a cool version of Shape I\'m In or Life is a Carnival.
The Who - I know this goes against the classic rock band thing I said before, but how about a mini-rock opera like A Quick One, While He\'s Away.
Just my two cents