Unavailability of xserver-xorg-video-tga currently makes xserver-xorg-video-all uninstallable on kfreebsd-amd64.The bug is probably here. xserver-xorg-video-all shouldn't depend on xserver-xorg-video-tga on !alpha. I'll fix it in the experimental branch, it's probably not worth it for lenny.
But xserver-xorg-video-tga is buildable on kfreebsd-amd64, it is already built on amd64 i386 kfreebsd-i386, so it should be built also on kfreebsd-amd64. It is really sufficient to add it into Architecture: line. For GNU/kFreeBSD it would be helpful to upload xserver-xorg-video-tga with kfreebsd-amd64 enabled into unstable now. Thanks for considering it. Petr