Answering for the USB side of things.
OS X itself should be able to detect up to 127 total USB connected devices through a single port.
I highly recommend reading this: https://superuser.com/a/330570/259665
I would also recommend getting a 4-port, powered USB hub to make sure that USB lag is not a factor when 4 people are actively using a controller.
If you actually want to connect 127 devices then it would require very careful planning to make sure that all of the USB hubs are powered properly.
Furthermore, if you actually connect 127 devices through one USB port then expect some very extreme lag when using your controller.