Mostly for you to think about and consider simply because you are in the planning stages.
You may, for example, select a router that meets your requirements and budget. However, if that router is not specifically supported by your ISP then the ISP can simply "oh well" any network or even internet problems that occur. Even if not directly related to the router itself....
Most home routers are very much the same in features, functions, performance. And there are FCC limits on wireless transmission power. So at some point any amount of advertising or "techno speak" is moot. Specs are often established in ideal circumstances that do not match the real world. Some features are almost meaningless or not really as they appear. QoS (Quality of Service) may not really provide what is expected. There are always trade-offs.
Just for example purposes:
https://www.linksys.com/support-art...ity of Service (QoS) is,and speed can be used.
Note "Media Prioritization".
Plan out the network as you envision it being. Devices, connections, locations, distances, where existing cables (of any sort) are now run or where they could be run. Does not need to be fancy - just a sketch. Very likely your plan will change for any number of reasons. As the saying goes: "No plan survives initial contact."
I could ramble on with suggestions, thoughts, ideas, etc. There is a better way.
Spend some time perusing the Networking and Wireless Networking Categories. Read posts and links that draw your attention.
Very likely you will find posts with the same questions that you have. And those questions are likely to be answered right there.
If not, then post accordingly.