I really think Sonos is the way to go at least in my experience - certainly have in-ceiling / in-wall speakers so you can pick your poison there but use Sonos Amps on the backend. You can have 4 speakers per amp (2 per channel).. depending upon the ohm rating. The soundbars are great as well and of course can double as speakers.
On the downside the system definitely costs more for arguably marginal improvements in sound vs other stuff but the ease of use and ability for dynamic zones really make up for it. It's fun to be able to demonstrate piping TV sound around the house. Of course if your clients are audiophiles then it will probably be a no-go.
These speakers have an excellent price to quality ratio and have used them in several client installs:
Have also gone higher end and used Sonos's "architectural" speakers which are great but pricey - they use Sonance's stuff (also great/pricey).
