http://focus.ti.com/paramsearch/docs...s&familyId=378
look for TAS3002 and TAS3004. Yup not as easy as ABC but i already used them and they gives decent results. TAS3002 will probably be the smartest choice. Of course you can find many other from aother company... google search dude

For the limiter, you're right. You read the signal in parrallel with the Audio Processor then you play with the volume VIA I2C bus. TAS3002 include a compression/expansion module but i can't comment on that section as i didn't used it.

Depending your skills, it willn't be easy to do, but really interesting project you have on hand now. Good luck!