You are actually after a workbench disk. The kickstart disk was only used on the amiga 1000 and a super kickstart disk was used on certain amiga 3000s. Since you already have an amiga 4000 you could write workbench1.3 onto a floppy or even use makeCD and the cdtv devkit to make a workbench CD. It is not exactly the legal way and it would be good to have an original workbench, but If you want to go down that path ask and we can assist you.
