Just to clarify. You want in-wall/ceilings only, not in room speakers, for the living room 5/7.1 system? What are you thinking of using for the center channel (in-room/wall)? I usually recommend the Polk speakers first for people on tighter budgets. They offer great performance/buck and are the easiest to procure. Do you have a size limitation for the sub? For sub recommendations, what are the dimensions of your living room?
Would you like a single mono or stereo in-ceiling speakers in the other rooms? Most two zone capable receivers could handle mono speakers, but a separate amp may be required for the stereo setups.
Where is the main listening position located in relation to a rear wall, for surround considerations?