DuaneB:
Why not just by a cheap off the shelf RC transmitter and receiver -
I guess "cheap" is in the eye of the beholder. Those are $80-$400, and do not hook up to the Arduino for actually sending/receiving data without significant modification.
The modules I already pointed at already speak SPI (the Arduino can do that on pins 11,12,13) and are one-tenth of the price of your suggestion.