Which all reminds me... if you have one of those usb thingies to plug your radio into a computer as a joystick for a simulator (like FMS mentioned above), the arduino with the same code, plugged into it, would let you try your control scheme in the safety of the virtual world.
Bound to save you time and money as you iron out the kinks.
This would also be a good quick 'n dirty way to make your arduino speak USB-joystick to your computer, by the way...