What about the 12" wizzys? I did try the markbass 210 back when I first got my gk and it was not a good pairing for urb. perhaps they would be better with the mark II? It also seems I no longer need a pre amp with the mkII. Thanks for all the suggestions, keep 'em coming.
The Markbass cabs definately pair best with their own amps. Give 'em a try again. They're nice cabs.