I have created a Cool Solutions here which outlines how to mirror the Security, Optional, Recommended and Kernel Only for ZLM, but they have changed things in ZLM 7.2 IR2...They have removed the command line option for the --category from the zlmmirror command, and moved it into the mirror-config xml as a tag under the catalog section, which at this time does not work. Refer to bugzilla #333347 to the status. According the end of the bug they are slated to move the command line option back in and have this all fixed by ZLM 7.2 IR2 Hot-Patch 1.
Disclaimer: As with everything else at Cool Solutions, this content is definitely not supported by Novell (so don't even think of calling Support if you try something and it blows up).
It was contributed by a community member and is published "as is." It seems to have worked for at least one person, and might work for you. But please be sure to test, test, test before you do anything drastic with it.