Happy user with a Boom in the Kitchen, receiver streaming to the living room and a Radio for the bedroom.

We are extending our house and I think we need another squeezebox, but I'm not so sure where to put the speakers and what speakers.

If I'm going to buy speakers, I've decided to buy AudioEngine A5 speakers for both receivers (buying an extra receiver).
However, the placement of these speakers is always BEHIND the listener. On the couch, the speakers would be behind and at the dinner table same thing.

1. Does it make sense to buy A5s if I'm planning on putting them behind the listener?
2. Alternative view would be to buy 2 (expensive) iPhone docks, where the audio in is then fed from the receiver. Pro: much easier placement, con: worse sound?

Any hints appreciated!