Michelle,
I've just seen this thread from some time ago. It looks like you didn't get much feedback, which is a shame.
Anyway, I'm interested to know whether you got anywhere with programming the TAS1020B. I'm in pretty much the same situation as you were back then, and have a PCM2707 for comparison.
I've seen mixed reports about even using the free version of the recommended Keil C compiler, but would have thought even the open-source SDCC should be appropriate with a little work (the calling convention might even need changing, but that should be feasible). I'm hoping to use the DFU mechanism to update over usb, which might be very convenient if I had the foggiest idea how set it up, esp. on the linux side.
Regards,
David