I think Eclipse still makes an in-dash AM/FM 6 CD changer. At least, my local Eclipse dealer still sells them. The mounting depth is a little deeper but I think the S has plenty of space.

I put an Eclipse CD deck and a DIN 6 disc changer as a double DIN mount setup in my wife's GS-R about 5 years ago and both units still work flawlessly. However, I have to say that I much prefer the Alpine CD deck that I have with WMA playback- larger song capacity, auto song labeling, and you can leave your original CD's in your house where they belong.