It's great to have choices.
1. The Roku SoundBridge decodes AAC on the receiving device, the SlimDevices Squeezebox decodes AAC on the server -- and streams FLAC.. Roku has an iTunes license, Squeezebox doesn't.
2. Squeezebox is tightly integrated with the OpenSource SlimServer with a web client interface. SlimServer can stream to iTunes or to the Roku SoundBridge (not documented).
3. SlimServer in my limited experience seems to demand a lot of machine resources, and is a bit flaky.
Decisions pending ...