geralexandr
You don't need to set up a server (you can if you want to but I don't), and you don't need a different Steam account.
You do need a master account to sign up for Steamworks (if I recall correctly). Once you're signed up for the Steam Site License, add each of your station's Steam accounts as a "user" through Steamworks. Then log in to Steam with that account on each station and go to the game's store page. From there you'll see any commercial license options to purchase. You're billed directly through Steam like any other purchase.
Just don't add the game on Springboard's commercial license platform to avoid being billed twice
