This is the system I put together initially;
Speakers (I use these, but really your budget will primarily determine what you might want. These sound great though. You will want either 4 to 8 ohm rated speakers)
https://www.parts-express.com/dayton-audio-cs620c-6-1-2-2-way-ceiling-speaker-pair--300-402
Another option
http://www.monoprice.com/Product?c_id=108&cp_id=10837&cs_id=1083702&p_id=6034&seq=1&format=2
Volume controls; one of these are used to control a pair of speakers in each room/location. These are impedance matching remote controls which allow you to use multiple 4 or 8 ohm speakers on a single amp channel and keep the load correct that the amplifier sees (dip switches on each control determine this).
(I use these, but depending on your amplifier, you may need higher rated ones)
https://www.parts-express.com/wired...ng-rotary-speaker-volume-control-50w--300-560
Distribution hub (this takes the input form the amp channels and sends it to each volume control) Note that you cannot just use this with the impedance matching volume controls or you will destroy your amp!
https://www.parts-express.com/wired-home-wh10sdh-10-room-speaker-distribution-hub--182-820
Amplifier: This is one area that there are tons of options... I started out using the zone 2 channels from my Onkyo AVR, but that was limited as the input could only be analog and the network performance sucked.
Eventually I switched to one of these:
http://www.amazon.com/dp/B00026BQJ6/?tag=atomicindus08-20
It worked very well, it has auto turn on so all you need to do is start playing music from whatever source you want (analog input only)
All these options above put together sound great, work very well and doesn't cost a lot.. The downside for me ended up that it was one source for everything, so there was no way I could listen to what I wanted in the garage while my wife listened to what she wanted elsewhere....
Also, in addition to locally streamed music from my server, my wife and I were listening more to a lot of online streaming (radio stations, pandora, Rhapsody, Spotify, etc). For this we could use one of our tablets for the source, but it wasn't really convenient..
My solution (I am currently building it) is to ditch the stereo amp and distribution hub in place of one
Rasberry Pi and an
amplifier module for each zone ( I will be using 4 separate zones right now; Kitchen/dining room, Garage, Living room, patio so I have 4 RPi's and 4 amps).
Each rasberry pi is connected to a single amplifier module and runs a special build called
Squeezeplug. This and the app are freeware, so no costs there.
Basically each zone now has its own source for relatively cheap. Using an app on each of our phones or tablets, we can control each zone completely independently or have them all play the same source for parties..
I am putting all of the equipment into a rack enclosure in my basement.
Let me know if you have any questions!