I really like KDE and Ubuntu but I don't need most of the KDE applications, like Kontact or Kopete that will be installed with the usual KDE.
Is there a way I can install KDE (4.7) without all those applications? It makes more sense to manually install the ones I actually use (like Konsole) than uninstalling many.
try
sudo apt-get install --no-install-recommends kubuntu-desktop
The https://help.ubuntu.com/community/MetaPackages is telling:
There has been package naming changes. I think that this is the current nucleus of the KDE:
The kde-baseapps is depending:
These may be useful:
Kubuntu 18.04.0 LTS now includes a minimal install. For fresh installs, I think this is a good alternative.
If you already have Ubuntu installed, like in your question, then
sudo apt install --no-install-recommends kubuntu-desktop
is your answer.