I haven't tried userlinux, but if you have apt configured with standard Debian repositories in /etc/apt/sources.list, you can install kde with:
Code:
apt-get update
apt-get install kde
You should probably also install the kdm login manager:
Code:
apt-get install kdm
More details can be found on the Debian KDE wiki:
http://wiki.debian.net/?DebianKDE