... if you have a lot of time try Debian Remastersys.

The well tested way to remaster Knoppix is described in Remaster HowTo (without chapter 3!); alternative you can use my scripts. Be aware, to remaster Knoppix DVD you need a free partition of at least 25GB size or a virtual drive of 25GB within VirtualBox.

Greetings Werner * http://www.wp-schulz.de/knoppix/summary.html
Own Rescue-CD with Knoppix (Knoppix V6.7.0 remaster)