which server hardware required?

Hi
Sorry, my English is not so good but I still try to make me understand.
I would like to open a server This server runs Linux.
My question now would be which system requirements need my server.
RP should be played or build and I thought so at about 30 - 40 slots

I would take even the minimal and the maximum system requirements pls

I hope you understand me

Greetz
Salasane

Are you using a home server or a actual computer server?