Hi Dembo! First of all, thank you!
Then, there are many solutions: I would suggest you to buy Toasterball on Steam (plus, this will support our work ;)). Thanks to it, you'll be able to play up to 4 players (with one keyboard for two players, and you'll need two gamepad for the two other).
In another way, you can assign two players for one athele (each player hold one key (left&right)), . You'll need tiny hands and more space but it should work ^^
I also guess that you can find on internet ways to emulate gamepad on a keyboard. Don't know how Toasterball might react, but you can still try!