Well, it takes a lot of time and effort to make personal one-man distros not to mention the amount of patience you need to trial and error everything.
I don't know about OpenSUSE, but for Fedora, there is a tool similar to Reconstructor called
Revisor using which you can create your own custom spins with codecs and all. However for any of such tasks on any distro, you *need* to have a fast net connection since it needs to download the packages, their dependencies, libs and all the she-bang of the packages selected.
My advice would be instead of starting a new one all by yourself, why not contribute and build up to an already existing one, an example would be Omega. This is a Fedora based custom distro with codecs and capabilities built out of the box designed by Rahul Sundaram with all Fedora branding removed.
Additional info can be found at
http://forums.fedoraforum.org/showthread.php?t=206943