I installed Ubuntu 13.10 about a week ago. Just today I went ahead and installed kubuntu-full to get KDE and it's associated programs. I want to keep the Unity login screen though (default when you install Ubuntu). I can't seem to get this working. Doing a 'sudo dpkg-reconfigure gdm' or 'sudo dpkg-reconfigure lightdm' and choosing either one of those does not get me there.
If I choose gdm, I just end up with a gnome login screen. If I pick lightdm, I end up with a KDE login screen. Doesn't seem to be an option for choosing the unity login screen (whatever it's called).