Papa,
The 9C does both PCM and PPM. All you have to do is Switch the mode, then turn off and turn on the radio. The just buy the proper reciever, either pcm or ppm. There are multiple threads on the subject of PCM vs. PPM, do a search, should find plenty on that topic. THe different packages that you see for the 9CAF and the 9CAP, are the exact same transmitter, they just come with different receivers. Hope this helps