Advice Needed: KDM or GDM?

I will be installing Ximian Gnome 1.4 under S.u.S.E. 7.2, During the installation process, I will be asked to pick a display manager to select the desktop. KDM or GDM. Is there any serious difference between them? How do I make sure that the manager I pick will send me to either KDE or Gnome? Thanks for the help dj tuchler