Depending upon what "sound" your satisfied with (i.e simple stereo, mono, 5.1, etc.), you may want to consider a simple stereo receiver that has "A/B" speaker settings. "A" may be the living room, "B" would be the kitchen area. You could set up wireless speakers via a transmitter (to avoid wire runs). The you would simply switch to "A", "B" or Both.
Sometimes I have to remind myself that I bought all this "stuff" to enjoy it!