I use a Buffalo 2 TB LinkStation Duo RAID (~£150 I think) for Sonos, Photos, Computer Backup etc. It works well and it hasn't died in the 3+ years I have had it.
I suspect any NAS from a reliable firm will suit you fine. A NAS will NOT have any effect on the sound quality of your music.
However, whatever NAS you buy back it up regularly to another hard disk which you store some distance away. All NASs can break down, even RAID ones which allow you to replace disks without loss of data, and we can all suffer little fires or thefts. Re-ripping is a tedious process.