I have setup one of my old PCs as the router. I couldn’t find a single router with multi-uplink here in Sri Lanka, but PC router is more flexible, IMO. I’m running Debian on the router and using Shoreline Firewall aka Shorewall for firewalling and traffic shaping/control. It took a good few hours to setup mainly because I mixed up the ethernet interfaces 😀 . Shorewall documentation on multiple internet connections and traffic shaping/control by Tom Eastep helped me a lot in setting up my router.