Considering Multiple ATV 2/Media Server

I have a dental office, and I'm wanting to put TVs on the ceiling. Instead of streaming cable, I would rather put Apple TV's attached to some hard drive. I have 4 chairs where I want this to work. So I have multiple questions if this will work. Any help would be awesome.

1) Can I stream 4 different movies, tv shows, music off of one server/one itunes account at the same time? The setup I'm thinking of is 4 tvs, 4 ATV2, wired to headphones to the chair, wireless to a MBP (w/ airport) or mac mini (server). Most important question or the below questions are useless.

2) What would be the best server? MacBook, MBP, mac mini, etc. l assume I need airport attached to it or some router. I'm looking for a variety of options, so patients can choose between short episodes of tv shows, movies, cartoons etc. Ie. not every appointment is long enough to see a full length movie, so tv shows on DVD/itunes work best. If I have 10-20 movies, 10-20+ tv episodes, and 1200 songs (12 gb) - how big of a hard drive?

3) I would prefer to add movies I already have, but have not attempted to add my DVD's to itunes yet. From here on out I'll buy them through itunes, but I need a jumpstart with my current ones. What is the best converter for this?

4) Will the remotes effect each other? All rooms separated by a wall, but ATV2 might be 15-30 feet apart.

5) I'm assuming I can only have one tv using Netflix. Right?

6) Is it possible to stream Pandora to at least one tv? I've read yes and no answers to this.

7) Right now I have an Ipod hooked up to a receiver for office music. If I can connect it to the media server, it would be preferred. So how would I do that? Directly to the server, ATV, somehow with the Ipod still?

Sorry for the long post. I just figured I'd lay it all on the table. This will save money in the long run rather than paying years of $150 per month cable bills. I'm already an apple user, just jumping into unknown territory with the apple tvs. So I tip my hat to the genius who can help me figure this out.