I understand that, but by enforcing a requirement for a RHEL/CentOS native tool, you are making work for yourself.
If your requirement is to restore from a disk image, the simplest way is to ignore kickstart altogether and let clonezilla provide the PXE kernel, which will restore the image.
You don't mention if this is a virtual host or bare-metal.
A more complicated, but entirely RHEL native way is to set up a Cobbler server and, using Cobbler and koan, create a backup image, which you can then recover to in the event of failure. Example here
. This scenario is designed for virtual deployments, but Cobbler is flexible, maybe it can be persuaded to work with hardware too.