We have been using my iMac as our central iTunes server (it feeds our Sonos home stereo system). For size and other reasons, I want to move this function to a standalone unit that isn't used for other computing. I am a newbie, but has anyone set up a server in Mac invironment that isn't just buying another iMac? What do you get? Sorry for what is going to be an easy question, but not sure what to purchase to us OS and act like an iTunes server?