Thanks for all the replies above
Having done further research I found that overwhelming advice was to go for Sonos - coz it's flexible, user friendly and works.
Today I bought the Sonos connect (plugged in to my router and main amp and speakers) and play 5 (wireless in the kitchen). Very impressed
. Easy to set up, great sound, control from phone, computer, ipad easy as pie
......I have music files on all devices, which can stream to the sonos sysytem no problem, but it seems like a good idea to have a dedicated music hard drive so that all music files will be available to the system at all times. I have plugged this drive into my Airport Extreme, and my mac can see this drive over the network and connect to it successfully... but I'm having trouble selecting this disc as my music library for Sonos
Long shot, I know, on an Alfa forum
but anyone got any tips?
Got it working now!
I found advice on sonos forum - had to simplify name of airport network - now all is good