General :: Sufficient Hardware And Methods To Stream Media In LAN?

Recently, my fraternity decided to use our LAN to stream media to our various bars, lounges and ballroom. Some of our playback devices, including an iPhone and a laptop, broke during a party, which is why we decided to have portable devices replaced with sturdy, interchangable and fixed hardware.

As this is going to cost some money and effort, we had better make a fully thought-through plan, which I am in charge of. Still, having never organized a project of any measurable magnitude, I would rather have this plan commented on here.

So far, I am planning to buy one central PC (2GHz, 512 MB RAM) acting as a server, and four identical PCs (1GHz, 256 MB RAM) acting as clients. The former would a) provide local files, stored an an external encrypted hard drive, and b) act as a NFS and SMB client to private systems in the same LAN to incorporate (and forward) data stored on those (as to provide one central point to change the configuration for their use). Futhermore, it would host /etc, /usr and /home of the individual clients to provide that at all times, the same software and drivers are used on all of them. The clients then would mount /etc, /usr and /home from the server, alongside with the both the directories on its external HDD and the ones it had itself mounted from other PCs. Each of them would have to be able to play back music, video files and terrestrial TV from a USB stick, with at most two of them doing so at a time.

Is this a realistic scenario? I so, would you have any recommendations for changes and could you point out pitfalls? The whole lot would have to be rather secure, as usually, there are lots of people coming and going, and we don't want our private data corrupted. If not, where did I go wrong? How would you yourself build a system like that?

And last, what software would you use? Is there a window manager which would be able to act solely as a means to display the three icons needed for TV, video, and music, and make it impossible to tamper with the system? And what programs would you use for playback to ensure maximum performance?

P.S.: Not that I'd suspect so, but is there a german lawyer present? Provided the individual files we play are in our legal posession, this is a legal scenario, isn't it? There would only be friends and other frats present at any public display.