How often do you have to sample the bands?  I think the PIC could easily handle
a software digital filter and look at one frequency band at a time.  Since you
don't need a really sharp bandpass, you could probably use a FIR and minimize
instability problems arising from coefficient quantization in an IIR.

BTW - Does anyone know of good, inexpensive filter design software that handles
coefficient quantization to 8 and 16 bits?

- Mark Sullivan -