Answer:
A decent portion of the KDE desktop can be installed without installing its applications, although this makes little sense since GTK+ applications don't really look right in KDE. You should be able to do this by using the command
sudo apt-get install kdm kde-base
P.S. The version of KDE in the 8.10 (Intrepid) repository is very old and known to have a lot of bugs fixed in later versions. Unless you have a very good reason not to, you should upgrade to a later relase.