I bought a firewall appliance based on an Intel CPU, with 4x 2.5gbps Ethernet ports, 8gb ram. Installed opnSense on it and been super happy even since!
A bit pricey the hardware, but it's been totally rock solid for almost two years now.
I have configured unbound with ad blocking on opnSense, and it has every single option I would ever want on it. Amazing stuff.