Hi,
5 years ago Fabien Lusseau published a BeOS Developer Edition 2.2.
It was available from several sites including BeBits (http://www.bebits.com/app/4058) but the linked resource is not more available (and I suppose it is since a long time yet).
The missing file is DeveloperEdition-1-1-boot-and-main.zip. Perhaps that an ancient BeOS dev or enthusiast has still that in a cdrom or a forgotten hard disk partition ?
Thanks.