Logitech Squeezebox Touch - Internet Streaming Music Player | eBay
Advantages over Sonos is that you could see what was playing, can have remote controls everywhere around the house and can use any speaker system you want.
Disadvantage over Sonos - it doesn't provide a speaker and support is now open source rather than via Sonos.
Long term Sonos will go the same way as Squeezebox as Amazon Echo and other similar systems will take the market...
Personally I would try an Amazon Echo/Dot and see how that works.