That computer will be great for small Minecraft servers. With those specs you could run a Minecraft server that could hold somewhere around 20 people. But this greatly depends on your internet speeds. It is possible to run multiple game servers on one machine. But with this computer you could not run a lot of game servers at once. Regarding hardware, you will also need a router that lets you forward ports. I have quite a bit of experience setting up Minecraft servers. If you would like help, feel free to contact me.