Originally posted by: ViRGE
If that's what you want to do, then the answer is "neither".
WinServer doesn't have a backup server application, only Windows Home Server does. The same goes for a web interface for half that stuff. It sounds like you need a WHS box for most of this, and perhaps a 2k8 box for "remote accounts" if you're talking about people needing a terminal server.
As for your additional software, Orb should cover your media streaming needs.