What about mounting the PCs under the desk? not on the floor but say at the far right on the underside of the table and use small form factor machines and have the IO on the back of the tables? If you're wanting to go for sleek that is
Also i thinking few suggesting wireless peripherals but not sure about input lag
Also i'm thinking some form of divider between the desks, not big office ones, but just enough to stop what i will call light bleed. So say you're streaming and someone is playing a FPS next to you you might get some weird light flashes
Also boom mic's on each of the desks to remove unwanted sound from hitting the desks etc.