I realise this does not answer your question (but at least boots it to the top of the list again) but why can you not use USB game controllers?? I am currently running 5 controllers from my computer. Before anybody asks....
1x joypad from the gameport
2x Joypads from a USB hub
1x steering wheel from the USB hub
1x Joystick again from the usb hub
Each of the joypads are of differing quality - typically only use one of the USBs gamepads but the others are there if required.