OK, I am looking for an FM modulator circuit (or IC if it exists) that will have a carrier frequency between ~30kHz and a few hundred kHz.
In the current plan for this device in which it will be used, I want 0-20kHz (audio signal) mapped to a ~1KHz variation in the carrier frequency, so that the audio signal modulates the 30kHz carrier wave from 29 to 31kHz. These numbers are ballpark, but within 10% or so of the final values (the tolerance on the key part this circuit will be feeding is poor).