You really need to figure out how many zones of audio you are looking at and how much discrete level control you want through those different zones and if you want more locations with speakers/stereo audio.
From what you are saying, it sounds like there is a huge open space and a theater space, and that's it. So, one surround zone with video and local sources, and then a second area with stereo only.
So, a single source with a speaker selector and amplifier for the speakers with volume controls in each area is certainly a very easy and basic setup which is commonly used. You get a controllable source, like a Sonos or Blusound product that's appropriate for you.
If you do have a list of multiple rooms with 2-4 speakers in them for stereo audio playback, then you may want to consider something like what Home Theater Direct sells.
Whole-house audio systems you can install yourself and control with keypads and smart devices. All HTD systems include a 30-day guarantee, 2-year warranty.
www.htd.com
I don't think distributed audio systems 'lower' the value of a home when they are done right. I do think that many aren't done 'right'. Remember, when you buy something like what HTD sells, it should stay with the house when you move. It is needed to make things all work.