I will try to answer only a couple of points, and it will not be very helpful. I _totally_agree_ that you want to have a complete distribution on some easily accessible medium, and you want to keep it around. If you keep getting updates you may -and I am not saying that you will- run into trouble. You can always play around with a system that was self-consistent when it was issued. VMs are great for this kind of experimentation. Gnome and KDE are "window managers" and modern window managers have taps (see our discussion on dbus) to more functions that just the X server (your display software that drives your screen). Those are highly configurable, but you need to invest time to learn the philosophy behind them and how they are configured. Sounds like you need a book on a given distro (pick one) and start diving into the details. SuSE is very good. RedHat/CentOS/Fedora and all of that are good and popular. Ubuntu is extremely popular, especially among n00bs. A book will do it for you, because I know you have sparse to non-existent internet where you live...