You can use some of the Go Flight modules like:
http://www.goflightinc.com/store/gft...ule-p-126.html (toggle switches)
http://www.goflightinc.com/store/gfp...dule-p-76.html (push buttons)
Not sure about
:
http://www.goflightinc.com/store/rp4...dule-p-78.html
And this nice one:
http://www.goflightinc.com/store/gfl...ule-p-123.html (Has 2 axis, use as Elevator Trim , Aileron Trim, gear lights will only work in FSX)
if above panels give a problem like not being detected ask gamepad/joystick buttons then you can always use their software to signal key strokes with the buttons: GF KEYS
http://www.goflightinc.com/software.shtml