Portable projetor with Mac Air and iPads

I'm looking for a good solution for some small office presentations where I can project my screen and share it for some presentations. I'm struggling with portability and simplicity for simply sharing my screen with my office staff for training on our in-house patient management software vs. a quality projector that I may use to watch / stream a movie for example from my macbook air and/or my iPad and other apple devices when a large TV screen is not available. Any suggestions are appreciated.

Thanks

cj