can i have two apple tv's playing at the same time?

Assuming your network has the bandwidth to support it, yes. (most reasonable networks should)

You can watch different content or the same content (although when watching the same content they won't be in sync because you'll be starting them separately from each Apple TV.

AirPlay will work with 2 Apple TV's but not from the same device, you'd need two different devices each to send a stream to each Apple TV.

I know it will work with air tunes (a branch of airplay). I would think the concept would be the same with movies. When you start steaming, is there an option to use multiple apple tvs?

Yes it works for multiple AppleTV watching movies, tv shows from one iTunes. I do that here at home. I do not know about airplay.