Lately I've been warming up to the idea of deploying a refurbished tiny-form-factor PC—like those from Lenovo, Dell, HP, etc—as a residential firewall/router (running either OpenWRT or pfsense).
I like that tiny PCs from even a few years ago cost about the same as a new high-end consumer router but have the added benefit of more powerful, upgrade-able components (with the drawback of higher energy costs, but that's okay).
The problem I've encountered is finding one that has either dual Ethernet ports or a PCIe slot. Some tiny PCs have these facilities but most do not.
Does anyone have any model recommendations? I'd like to set up some alerts on Kijiji and eBay.