KDE has a setting to switch the cmd & command keys so that e.g. command+c copies instead of ctrl+c. This works in all KDE apps (it will not work if you install any Gnome/GTK app, though). I forgot the setting but its something in advanced and used to be called Emacs key binds, but now I think it just refers to the keys.
Anyways, beyond that, have a look at Kinto which tries to do everything in one box, but it is an additional software you have to run: