Richard,
I talked to Joe about NFS. He says it should be pretty easy. You'll have to install the appropriate RPMs (knfsd) and perhaps (knfsd-clients) from the Red Hat distribution. Then create the file /etc/exports, something like this:
/home 192.168.1.1/255.255.255.0(ro,no_root_squash)
/etc 192.168.1.1/255.255.255.0(ro,no_root_squash)
Essentially, you just list what you want to export, which IP addresses have accesses, and options.
Then either reboot or run the command:
/usr/sbin/exportfs
and your Ultrasparc should be able to see the directories.
Good luck!
Kim