Why don't you do anymore DYI videos?
Its better to just use a router designed to be a router. I have run internet through custom built routers, servers and more but have found that there is a significant dent in speed and latency. Its fun to do but is far from practacle. Huge power consumption (Especialy when you use a server as a router like i did) in comparison to a standard netgear router, no real major benifits and huge dents in performance. I wouldnt bother.
Repurpose some of those old computers into servers for your network. Hell, even setup a lab