No, not stupid. Just need to clarify...
Do you have localized SmartTV's, BD Players, Game consoles (xbox/ps3) at all/some of the locations?
If so, you could utilize PLEX to access your content on your server by installing PLEXserver at the source of the files, and the client apps on each device.
For any TV that does not, you could get a ROKU or other streaming device to use as a client and install the PLEX client. Each client is in the range of $50-$100 depending on what you might prefer.
See this forum for more details: http://www.avsforum.com/forum/39-net...ent-streaming/
If you've already run HDMI, perhaps you can use the same chase for Cat5/6 to avoid wireless. Wireless can be used, YMMV depending on the strength of signal.
As far as a computer for housing all the movies, take a peek at Assassin's HTPC Blog: Hardware Guide
for some ideas. A modestly build computer can be put together to stream all the content, most of your money will be spent on storage/HDD's.
Once you figure out what direction you want to go, report back, and we can help you along.