with speakers in key rooms and a AV receiver input and output in a central location
I would urge you to think carefully about that. Do you really want music in one room, but you have to go to another room to control it? And do you want to be limited to the same music in each room, rather than the ability to have soft background jazz or classical in a conversation room AND kid music or sports in another room?
You can do what you mention... have one central source and speakers in multiple rooms with only volume control in those rooms. Or you can have separate systems in each room.
The separate system route sounds expensive and complicated, but it can actually be less expensive, simpler, much more flexible and higher quality. (I think almost everyone here would recommend separates. The "whole house" audio thing sounds like a better idea than it really is.) Either way, you can have some in-wall wiring done during construction.
Think about it... let us know what you decide and we can dive into the details to provide you our best suggestions.
