Here’s what I would do.
Router: I like ubiquiti, so UDM SE.
Switch: I’d go with a 48port Poe switch probably at least pro version. Connect this switch to the UDM SE via the SFP+ port.
AP’s:
I’d go ceiling mounted AP’s. Tons of people like the U6 pros.
Your ISP gateway/modem should be in the same spot as the above.
Use Cat6A and fiber if you want to future proof, not Cat8. Also run more Ethernet than you think you will need. If you need 2 in a spot, run at least 4 unless you are absolute that you will not need more. Utilize fiber on the run for the outdoor AP and then connect that AP to a Poe switch. This protects your main equipment from an electrical surge coming from the outdoor AP. Your exposure is the AP and the switch you use to power the AP.
Make sure your networking closet is well ventilated, has dedicated power(at least 20 amps, maybe have a 20amp line and then something more so you can utilize a higher VA UPS. Then install a UPS. And plug everything networking into the UPS.
I can’t tell you about your AP placement as I’m not in your house.
Hire someone/a company who is skilled at low voltage wiring.
I could theoretically have done all of it myself, terminating the cables really isn’t that difficult. I got the equipment and set the equipment up. But I did not run the actual wires, and watching them do it. I know my strengths, they saved me days worth of work. And I wouldn’t have done as good or clean of a job. They should be able to help you with AP placement as well.
A good rule of thumb is, everything that can be hardwired is hard wired. If you think you will need more ports, add them now. If you need. 2 ports at a location, make it 4 or 5. Now is the time to do it. Run fiber to the locations that will require the opening of walls should you need to run more lines. If you are setting up an out door AP or location, run fiber to the exterior wall, connect it to a switch, then use the switch to connect it the device to the network.
I would go with a full unifi stack for the hardware, I think it’s the best bang for the buck hardware for this purpose. If you hire an A/V company, they may want to use Araknis, because of your home automation and Sonos, but I have no experience with it.
Make sure the network closet has adequate ventilation.
All your runs come to a patch panel. You want cat 6 or Cat6A depending on home size. pure Bare copper. If anyone recommends CCA, ignore them and find another contractor. A good UPS is a must.