Forgive me as I have not been keeping up very much with what is happening with the desktop plans for Red Hat 8, but it was my impression that they were planning on meshing KDE and Gnome together into one desktop, but using the Gnome UI. I personally perform Gnome over KDE for a variety of reasons. I find it to be cleaner and I got made fun of by my Linux guru friends when I first started using Linux and installed KDE (lame reason, I know, but I did find that I like Gnome better). Come to think of it, they made fun of me for installing a desktop period. Anyway, If it does end up that you do not have a choice, then the non-newbie friendly solution would be to build your KDE desktop from source and use that instead.