Just install Kde. It wud be better if u keep gnome too. U may like to fiddle around with themes, desktop etc. So in that case variety wud be nice!
KUbuntu => Kde (by default)
Ubuntu => Gnome (by default)
XuBuntu => Xfce (yea)
U can install Kde,gnome,Xfce all and more like fluxbox, enlightenment, blackbox etc and then u can switch to whatever desktop manager installed whenever u like!!
Just like u have winamp,realplayer,windows media player to play music files, similarly these are desktop managers!!