Perhaps this will help you:
http://www.harkness.co.uk/other/RHEL4_custom_dvd.html
It is for RHEL4 but you may search for a more up-to-date documentation.
Another solution is to create a tar archive of the master system's filesystem, build a custom kernel, that has support for all required hardware on the target system, create an initrd with some tools (fdisk, mkfs, cp, mv, ...) and replace /sbin/init with a custom script that creates the required partitions and filesystems, install the boot loader and extracts the tar archive and reboots ...