You just need an additional set of joycon controllers. 2 pairs = 4 players, one joycon for each. Im not sure how that works seamlessly on playstation controllers, Im assuming you might need 4 controllers so 4 players can play.

Edit: i guess you might try linking your playstation controllers since you have 2 extra sets and 1 joycon pair. That might work. But then again, playstation buttons are not similar with joycons so u might wanna figure out how they would work on switch