First of all welcome. Second you have double posted. This causes confusion so please delete one post.
I have just built a new home and moved in 2 months ago and have put in three systems. I built an AV system in our previous home 13 years ago. I will link you pictures.
Rule number one is to NEVER place any AV cable behind a wall that is not in conduit. The conduit can be steel, plastic water pipe or Tech Tubes. Believe me technology changes and you must be able to change cables without pulling your house apart. I had to change cables in the last place and it was easy.
Along with the AV think carefully about your Ethernet infrastructure. Make your AV room the nerve center of your homes Ethernet/Internet infrastructure. Fixed systems are best hardwired. Use Wi-Fi for portable systems.
Next think about access. Equipment chases are your friend so you can get behind installations.
I don't like wired all house systems. You are better off with discreet systems. For background systems go wireless with systems like Sonos offer.
Now for your main AV room ATMOS system I recommend you follow Dolby specs to the letter. Ceiling speakers are best for height speakers. Where you wife does not want free standing speakers seriously consider in walls.
You have left this a little late. This all takes careful planning and involves an awful lot of work. Think things through carefully and in detail. You only have one crack at this and serious mistakes are common.
Here is a link to the build out of the three systems here.
Here are some links to the former studio
Speaker build and installations.
The former studio over he years.
I had cause to make some comments about Ethernet infrastructure this afternoon and copy them here for your reference.
I should say that all this is wired and not Wi-Fi. Wi-Fi is ONLY used in this new home for portable devices. Anything else fixed is wired to a local hub and then up to the studio patch bay and hubs. There are three local hubs. The studio chase has a rack mounted 19" Ethernet patch bay and two 19" mounted Ethernet hubs. Cat 6 throughout run to and fro the studio chase in Techtubes. Router is Netgear Orbi Mesh with units on each of the two floors. There is full 350 mps all over the home with no dead or low signal spots.
This is the third installation I have done with Netgear Orbi Mesh and so far zero problems. This Netgear Mesh was brought up before we moved in so the elevator could be certified. So far there has been no slowing and zero reboots. The whole system has been stable. I mention this as others infrastructure could possibly not be as robust or stable. How much this contributes to the results I get, I can't comment. But I have tried to adhere to best professional current practice on this part of the home infrastructure. In the modern home the stress on this part of the infrastructure is enormous. Just about everything needs access and often both ways.
Talking of both ways, I suspect all of you are aware of hacks to alarm systems in the news lately. Any device that can be accessed via the Net from outside opens up a huge vulnerability. In fact it pretty much gives the world the keys to your kingdom. So to enter our Network you have to go via an encoded VPN. My eldest son wrote the software. This is above my pay grade. Anyhow a lot of routers to not support access via an encoded VPN. The Netgear Orbi Mesh does which is another point in its favor.
I have said before that this Netgear Orbi Mesh is head and shoulders above any system I have encountered before. This is another surprise and I have had poor results from Netgear products previously. They knocked this ball out of the park though in my view.