Multizone Stereo System Setup

The previous owner of my house was a serious audiophile but when he moved out all of the components went with him except for a Niles IRP 6+ and a Holland Signal Combiner Model SC-3. Five rooms have speakers: Four rooms each have a pair of 6" speakers and the family room has four 6" speakers. I know nothing about stereo systems and basically want to listen to radio stations and wirelessly broadcast my iTunes library through the system. At most I would want to listen to music in three rooms simultaneously which would involve a total of eight speakers. Is it possible to power this system by buying/installing a single multizone receiver with integrated amp? Thank you.
You really should get a solid power amp like parasound to run the system. The internal amps in most receivers can't hack it. You will also need an impedance matching speaker selector. This is where all of the speakers will be hooked in to. Finally, you will need something to turn the sound on/off in each room and adjust the volume. To have IR capabilities would be preferable in each room also (this way you can use a remote control in any room where there is sound).

The other problem you face with the iTunes is that you can't control this with a remote from around the house. The best you can do is to turn it on and then wander the house. radio is a lot easier.

You really need to find out if there are in wall volume controls and or IR receivers in the walls. With an IRP6+ there probably are or are cut-outs and wiring just covered up. If so, this is your equipment list:

Denon 395 multi-zone receiver
In wall volume controls or volumes with IR
if you want IR, you will need niles to go with IRP 6
A good 6-12 pair speaker selector(just push button is fine, no volume needed)
1 IR flasher to go from the IRP to the receiver.
If you are going to "crank" the music, you should get an external power amp of decent quality and use the pre-amp outs on the receiver.