specs

Hi guys, Hoping someone can help me with the difference of the above two units? Seeing a lot of both on ebay at fairly attractive prices but I cannot seem to locate a spec sheet for the "a" version anywhere. Given some of their other models I assume that it is an updated version with slightly...

The question: What specs should I be looking for if I wanted to build/buy a server that is able to run 4 dedicated game servers simultaneously on 1 server? I'm currently looking for a server that can simultaneously run: Ark Survival Evolved Space Engineers Satisfactory Minecraft The server is...