Soekris Engineering produces embedded communications devices such as the net5501, a small yet powerful x86 computer that works extremely well as a router/firewall running FreeBSD distributions such as m0n0wall.

Most of their business is in relatively high volumes with business customers, but if you're in the market for a reliable custom firewall/router/etc. and can navigate their relatively cumbersome ordering process, they'll happily sell you one or two units.

If you stop by their office, it might be worth grabbing lunch at the Live Oak Café on your way out.