To add to the (fine) advice you've already gotten...I'd suggest that you're looking at things backward. You're asking which is the best method, and then, presumably, you're going to tailor your act to the method.
It really should be the other way around. Decide for YOURSELF what would: A. fit your act and persona; B. fool YOU the most. That is: what would be a most entertaining, impressive, and logical book test to YOU? Something where a number is chosen from a phone book? A word from a dictionary? A sentence or paragraph from a famous work of literature? Something with a book furnished by the spectator him/herself? Maybe something from an atlas, a travel guide, or a thesaurus?
If you can decide what you want to accomplish, and what the conditions must be, chances are you can find a method to do it, and people here can undoubtedly help.
ESPECIALLY if money is no object. :-)