I wasted a day getting this going with even minimal success on KNX 4.0.2 till I tried using Rinks suggestion to generate a XF86Config-4 replacement file with all my hardware installed. I figured it could NOT be that easy. Apparently it is.

Using "init 3" from a root shell to exit KDE, I ran the "X -configure" command (as root) and copied the resulting XF86Config.new file to /etc/X11 as XF86Config-4. I restarted KDE using the "init 5" command. Thinks were functional as both montiors worked, but FAR less than perfect (goofy resolution, mismatched color depth, screens went black and white when running xawtv, etc.).

So I used XF86Config-4 files saved from separate live CD boots as a reference on what was needed; first I installed just the card and monitor i was using for monitor0. After saving the XF86Config-4 file for monitor0, I removed that card and monitor, and performed the same steps using the hardware for monitor1.

Using the information from the two additional files, I modified the file created using "X -configure". Happy to report that things work spectacularly now.

I may have to get an additional card now so that I can span three monitors...

This post was invaluable in getting this going. Thanks all...