tl;dr is: scrounge up some hardware, preferably on a recent-ish Intel platform with an igpu (i think 8th gen+ is the sweet shot), and then get a slew of storage. Pick a base operating system (I like ...
LAN-based game servers are also a popular alternative offering for conventional arcades, and an entire business is springing up around the "PC room" and "LAN arena" concepts. Multiplayer game boxes ...