IMO the Sonos is by far the better option, and if you have an iphone or itouch you can get a free app to control the system saving you money. Yes the Sonos is not cheap but really so easy to set up, supports all music files, does what it says on the box and customer services are great help, if you need it. I would also get a NAS hard drive, transfer the files onto it, and and connect it to router so that the computers don't need to be on to play music.
Look for a local shop that may have an ex-demo for sale.
I really think it was the best money I have spent in a long time, and using Napster gives you limitless music, I don't use my saved music anymore as my playlists on Napster has everything and more that I have ripped.