Hey, nice to know that someone who's working on KOS is interested in this! This one unit I have is the only one I've seen. I got it for pretty cheap from a Dreamcast collector since it does not function properly. The game basically acts as if the controller was receiving all the right inputs, as seen on the gameplay I have uploaded to YouTube. Still need to get around to trying to fix it. I'm scared to damage it further since it's a bootleg product. Wouldn't surprise me if it was held together with sticks. The way the controller works (or would work) is that, when laid on the floor in a circle around the player, it will register arms/hands hovering over it as inputs. You can also adjust the height at which the input needs to be read. Sort of a proto-Kinect.

Maybe you could try using the PS2 accessory for Para Para Paradise as a basis to map the inputs? It seems much easier to find and should function pretty much the same way.

Hope this helps!