I think C2000 is most suitable for you, it have a ADC and PWM to receive and create the signal. C5000 and C6000 don't have ADC and PWM, it need and external converter or codec.
C24xx are up to 40 MIPS, in 16 bits
C28xx are up to 150 MIPS in 32 bits
I used both and works ok, you must see if 40 MIPS 16 bits are enogth to your project, then jump to C28xx if it's not. If you want to be sure start with C28xx, and then optimize and go down to C24xx.
DSPics are up to 30 MIPS and 16 bits.
Good luck