build to your needs and safe money. When you truely want 1Gb/s throughtput i would say build yourself.

INTEL dual NIC to start with. hardware offload. get one with a low profile bracket

Dell optiplex 7020 SSF use it with a I5 4th gen cpu 8GB ram and a 128GB ssd.

DONE!! you have a powerful pfsense box.

I ran one for a few years before i build my own 1U box