Im planning a project to create a automated RC car. To do this i would need a RC transmitter which connects to the USB. I have thought of a number of ways to do this and not sure if any will work and would like some advice.

1) To get a 27.9 or a 40mhz transmitter, I cannot find any so thought i might need to build one.

2) To get a 2.4ghz transmitter and a 2.4ghz reciever and change the original reciever of the RC car.

3) Using a microcontroller such as a stamp, or a arduino board or phidgets board. (need to research on this more to understand if it is possible)

Has anyone done this before?