My german is rusty so I won't attempt to answer in it although I understand you just fine. I ported gentoo to the pegasos a couple of days ago. You can find a beta install kernel here: http://dev.gentoo.org/~dholm/ppc.html. You will also need an install cd, I recommend: livecd-g3-grp-1.4-cd1.iso. I also recommend getting livecd-g3-grp-1.4-cd2.iso to get your system up and running as fast as possible (it contains precompiled packages).
If you hold off for a couple of days I hope we will be able to provide installcds that has pegasos support on them already and the powerpc installation guide will be updated to reflect the pegasos. (Ther are a couple of things to take into consideration when installing gentoo on the pegasos, like not installing a boot loader and some special kernel options you need to enable).
I have tried with the live-ppc-1.4 CD (1 CD) but I guess it was the wrong one. It gives me some Input/Output errors and stop on the prompt wiht "Enter runlevel:".
I used the livecd-g3-grp-1.4-cd1.iso when I created the install kernel. The guy who is official in charge of the livecds is working on an official Pegasos-enabled cd. Hopefully it will be ready really soon, it should make it much easier to install.
