The command cfgadm works on Solaris 8 as well, only the format is little different. Can you try the following:
cfgadm -al -o show_FCP_dev
Host Utilities Kit ( also called Host Utilities) for Solaris will work on Solaris 8 just as good as on Solaris 10. I didn't see any Solaris version in the setup requirements section. So I assume it should work with all versions.