Right, you would not have reached the AV wizard by this point, it is part of the LMCE install (i.e. after you click the LMCE icon); it is not part of the KDE install.
Is this machine just going to be a standalone core, or do you intend on using it as a core/media director combined i.e. hybrid? In other words, will you watch media and things on it, or is it just there to "power" other media directors? If you intend on using it to watch media, that ATI card may give you problems.
Firstly, apologies if I have any of the following wrong, but I think it's right. If you press Ctrl + Alt + F2, the writing should be big enough for you to read. From there you can do the updates as outlined in the wiki. Once you're done, do Ctrl + Alt + F7 to take you back to the desktop, and double-click on the LMCE icon (even if you are doing it blind). Then be patient and wait until it finishes, it can take a long time! When done, you can restart the computer, and then you should see the setup wizards.
Good luck!