I have used the squeezebox stuff and it works a treat. Heard people say the Sonos is better at multi room, but i have a boom and squeezebox and using the Ipeng app on my iphone or ipad it controls the devices in two different rooms with ease.
I have a few internet radio stations added to favourites, easy to access that way.
Loads of plugins, like Last FMetc too.
I use my PC without using itunes, many NAS devices are available with squeezecentre already installed.
The squeezebox is smaller than the sonos, which i think is better if you already have hifi as its easier to hide the box.