The 9C will transmit in both PPM (commonly just called "FM", even though PCM and PPM are both FM) and PCM. These two modes are unrelated to synthesized or crystal TX modules and receivers. If you buy a 9C with a crystal TX module, you can use any negative shift PPM RX with it, and a Futaba PCM RX with it (PCM is different among brands, but PPM is not). If you get a 9C with a frequency synthesized module, I've heard that some other brands of PPM RXs may not work with it, and of course, only Futaba PCM RXs will work with it. IMO, this isn't an issue, as long as you don't currently have a non compatible RX... there's plenty of PPM RX brands out there that will work just fine with it.

The 9C is a great radio, I have the 9CHP, which is the heli version that comes with a PCM RX. I fly a PCM RX in my Heli and in one of my planes, and PPM RXs in all the rest (Hobbico and Hitec brand PPM RXs). If you have the $$$ to shell out for a 9C, I think you'll be very pleased with it... I know I am!