I am very interested too in putting a IDE-CF interface in my 4000. Unfortunately I have little information, and many questions...

One question: I often heard that it is necessary to use a MS-DOS file system on CF-drives... but people say so because they intend to use the CF to swap files Amiga to PC or because it is really a requirement of the CF technology?
I need the CF for Amiga to Amiga swap, can I use an Amiga FS on a CF?