These mini pcs are a godsend: 12th Gen Intel N100 Firewall Computer Soft Router 4x 2.5G i226 i225 LAN NVMe Industrial Fanless Mini PC a.aliexpress.com/_mPBQflM
Cheap and more than powerful for opnsense and adguard on top (recommend over pi-hole).
Home assistant just run the new install script on proxmox to setup a vm. Copy your data over, usb pass through your radio hw and good to go.
Docker on lxc also works and you can probably swarm your containers over.
TP-Link Omada EAP line is rock solid for cheap managed access points. You can even run the controller in an lxc full local.