Not the answer you're looking for, but I put a 6 disc indash changer in the stock head unit spot. The problem is there are few aftermarket manufacturers out there. I used one from a Mazda, but Ford and Toyota make them as well.
I went with a single din MP3 capable head unit. This left room for a single din CB radio. Since you can put 99 songs on a single MP3 cd you don't really need the changer just some time to author the Disks. Of course almost a year later and nothing has been installed yet :tear: