Need some direction on hardware for home network

Have you tried looking for an official openwrt build for your Airport AP’s? Flashing that would give them full VLAN and multiple SSID capability. Everything a unifi switch can do plus more.

I’m running 1 tplink tl-wr940nv6 as an access point and another tplink tl-wr841nv9 as a repeater for both of my wireless networks. The DMZ vlan starts on an extra gigabit nic coming out of the pfsense box, and going to a second port on the tplink router, that is tagged for that vlan, effectively using the tplink router as an advanced switch and wireless AP.

I paid no more than $40 for both tplink routers. You can repurpose just about anything with the right software. Openwrt IMHO is a more professional piece of software than what the unifi AP’s run.