It already is like that.....
Ok, you first insert an install disc, and with Debian you make two files (rootfs - this becomes your virtual HD on your HD, and swap - Swap file)
Now, you have it installed. If you choose to install packages (KDE, xmms, etc) later, thats your responsibility. To start it up, you either use the boot_fatx cd, or, copy the boot cd to your HD and use it like an evox menu.