I would like to rephrase, I came off as a complete a-hole earlier, but I was just kinda pissed off at something. My apologies:
Mentalism is a great way to convey an audience, no matter how big. A simple prediction effect can be developed into a full 10 or even more minute routine. "Mind reading" is also great. If broken down, these effects are usually very simple, allowing you to come up with a huge story, and personalize the trick fully. And the amount of tools required, or lack there of, make it perfect for any scenario - up close or on stage.
Card magic is also going to be great, but to do this, you will need a way for everyone in the audience to see, so it may not be perfect for a large venue. In a medium sized venue, super visual card magic may still be hard to see, but demonstrations based on major sleight of hand and gambling demonstrations , such as Cutting the Aces by Marlo, will be very good, because the whole audience can see the effect (because you wouldn't see the method up close either).
Unless you have a projector, or a large screen, coin magic will be very hard with normal sized coins.