the xbox is already usb compliant you splice the cord and match the colors and leave the extra one hanging. you still nead a driver though. as far as making your own button relay's probably any controller will work just as long as you put part of the keyboard in it. and just get windows to recognize it has some sort of hot-swap keyboard. or just make the cord real long and half way down leave the rest of the keyboard. chances are you'll need it anyway, ie changing weapons, grabbing a grenade, stuff like that. but if you do get this mod up and running as well as looking good with some style let us know. or seing if you can daisy chain the buttons to the controller. that way you could use either the keyboard for you w,a,s,d, buttons or the joystick that sticks out of the keyboard. you could even make it detachable. anyway if this helps or hurts let me know and keep me at least posted on this.