Sonicwall tends to be somewhat expensive.

I'd suggest looking into ubiquiti unifi.

Central controller with several access point hardware options and configurations (including a repeater configuration), and the cost is very reasonable.

The main downside is that they frequently update the controller software and AP firmware, and don't always test as thoroughly as they should (resulting in occasional bugs). I turn off auto-updates and only update on my schedule a couple times a year in case the update results in unexpected downtime.

I'd look into a 'mesh' system. Many out there, I happen to use ASUS.

Some quick reading:
https://www.tomsguide.com/us/what-is-mesh-wifi-router,news-24580.html

https://www.asus.com/microsite/AiMesh/en/index.html

I also recommend Unifi. I did an install in a 50,000 square foot building and it works great with 30 access points.

I’m using the UAC-Pro, US-48-500w, US-48-G1 and Netgate 1537 running pfSense. I have since used the same setup in a 9,000 sq ft building and a smaller retail space.

ForceFlow Is 100% correct about the software update bugs but if you keep pfSense up to date you can mitigate most security issues from not updating the Unifi devices frequently.

This site can be helpful to use although it will try to get you to use their hardware as a router.

https://design.ui.com/login

I have Unifi in two homes with 10k ft coverage, including outdoor space and agree with the previous posters - solid system, frequent upgrades are painful. Set to manual update and it's the best prosumer solution I could find...and I tried a few.

I have 4600 SF over two stories and a 600SF pinball house behind the garage. After trying a few systems I have happily settled on Eero. It’s extremely simple to setup and can be easily expanded or upgraded (I haven’t needed to) by purchasing new plug in units.

I have a cable modem plugged into an Eero by Cat 5 and the rest are wireless plugged into wall outlets. This is, by far, the easiest system I have owned. Also, I like the ease of use on the iPhone app.

Best of luck.

If your access points/repeaters are wired, the ubiquiti gear is your best bet. It’s easy enough for most people to get setup, and there is a ton of training material out there.

If your repeaters are going to be wireless, the Eero mesh systems do a great job and are very easy to use and setup.

I personally use a nighthawk mesh system at home, but would have jumped to the eero system had the price been a bit more affordable for my needs.

I also, not to detract from Unifi (with cloud controller), have 2c to share - the Sophos router and access points are extremely easy to set up and manage, and can also be set up in mesh.

To be sure, Sophos XG routers are business-class but have some fantastic filtering/proxy services to shield endpoints from bad web sites/darkweb/vpn/etc...

Sophos Central (web service) is free to create and manage APs from. It's drop-dead simple and deeply configurable.