At the very least; First of all, if you're interested in installing KDE (or KDE support), you will have to make sure that your USE variable contains the kde and qt flags. For those of you interested, Qt is the graphical widget library KDE uses.
# These settings were set by the catalyst build script that automatically built this stage
CFLAGS="-O2 -march=pentium4 -fomit-frame-pointer -pipe"
USE="X mmx sse gtk2 qt alsa cdr cups foomaticdb mozilla truetype -kde -gnome -arts -oss xmms"
ALSA_CARDS="snd-intel8x0" This is mine,I use fluxbox,cups for printing and alsa for sound.I'm no expert,just read alot over at the gentoo forum,good luck