To choose your distro you must first decide whether you want a a stable distribution (debian) or a bleeding edge one (arch). Then you have to decide whether you want it to be a rolling release (tumbleweed) or a fixed point release distribution (fedora).
There's a lot more that could be said about each of these distros, but they all have KDE sessions.
You can update fedora through the terminal which skips the reboot part.