Friedman is supremely quotable. I would recommend that you re-watch the Free to Choose series for ideas… not only does he have great quotes, he was extremely talented at devising arguments to help people see why capitalism is a) not the boogeyman that socialists paint it out to be and b) the only possible basis for prosperity and a just social order.
Frederic Bastiat is also hugely underutilized … extremely quotable and he has a very elevated style. His stuff could be place in a visual context that communicates “classy”. I would particularly direct your attention toward The Law and The State.
Sowell is another very quotable guy. Walter Williams, as well, though he’s more conservative than libertarian, so have to be careful with his quotes.
Mencken, Hicks, Carlin, are the greatest satirists to live in the last century, IMO. Despite the fact that they were not “libertarians” per se, they often leaned that way and as consummate wordsmiths, managed to compress entire dissertations’ worth of libertarian thought down into a couple sentences.
Also, don’t forget to review the Low Content Quote thread, there are some amazingly good quotes in there.
Clayton -