How much wifi and open-source do you really want?

If you are willing to go with commercial hardware + open source firmware (OpenWRT) you might want to check the table of hardware of OpenWrt at https://openwrt.org/toh/views/toh_available_16128_ax-wifi and https://openwrt.org/toh/views/toh_available_864_ac-wifi. One solid pick for the future might be the Netgear WAX2* line or the GL.iNet GL-MT6000. One of those models is now fully supported the others are on the way. If you don’t mind having older wifi a Netgear R7800 is solid.

For a full open-source hardware and software experience you need a more exotic brand like this https://www.banana-pi.org/en/bananapi-router/. The BananaPi BPi R3 and here is a very good option with a 4 core CPU, 2GB of RAM Wifi6 and two 2.5G SFP ports besides the 4 ethernet ports. There’s also an upcoming board the BPI-R4 with optional Wifi 7 and 10G SPF.

Both solutions will lead to OpenWRT when it comes to software, it is better than any commercial firmware but there’s a catch about open-source wifi. The best performing wifi chips are Broadcom and those don’t usually see open-source software support**. MediaTek is the open-source alternative and while they work fine they can’t, unfortunately, beat Broadcom. As most hardware is Broadcom they have hacks that go behind the published wifi standards and get it go a few megabytes/second faster and/or improve the range a bit.

DD-WRT is another “open-source” firmware that has a specific agreement with Broadcom to allow them to use their proprietary drivers and distribute them as blob with their firmware. While it works don’t expect compatibility with newer hardware nor a bug free solution like OpenWRT is.

Side note: while there are things like OPNsense and pfSense that may make sense in some cases you most likely don't require that. You've a small network and OpenWRT will provide you with a much cleaner open-source experience and also allow for all the customization you would like. Another great advantage of OpenWRT is that with a great router like the BananaPi BPi R3 you've the ability to install 3rd party stuff in your router, you may even use qemu to virtualize stuff like your Pi-Hole on it or simply run docker containers.