A good solution for music server is some form of NAS (Network Address Storage). These tend to be a small standalone box that can easy be hidden in a cupboard. It important to remember that lossless formats require significant disk space, a average FLACed CD needs about 300MB. I use a NAS with one Terabyte of disk storeage (that's 1000GB), which uses RAID5 to protect against hard disk failure. Just think you have spent five months converting all of your CDs to your music server and then you lose it all when a hard disk fails!

The point about lossless formats like FLAC is that the bit stream that exits the ZP80 is identical to the bit stream that originally came off the CD. The major decision to use Apple lossless or FLAC is not how it will sound but how happy you as a user is in using the tools to RIP the original CD. Also Apple lossless is a closed system and you depend on Apple. FLAC comes from the Free Software comunity and just for that reason gets my vote.

A great place to find out much more about the Sonos is on the Sonos forums, have a look here.

http://forums.sonos.com/

S. Kench