When installing RHEL 5, it doesn’t matter if you deselect all the packages during the installation. You’ll still end with the @dialup and @java groups.
If you do a kickstart installation, you can set your %packages to
This also might save you the disks changes (all or some). This will result with about 900+ MB for / (not including /boot). If you want something even more minimal (e.g. only for firewall) you can choose the “%packages –nobase” option.