I’ve been doing this since 2005 with just my NAS and mediamonkey or foobar2000. Additionally, Sonos can index the NAS directly over SMB, although they have not really put much effort into fixing bugs in their implementation it still works well enough. Any upnp/dlna streamer that runs on your NAS (plex, twonky, etc…) should be able to handle other situations.

The nice thing about these media servers is support for mobile etc