This is a great tutorial. Just had to iron out a small "bridge" error:

there seems to be an error in the vmbuiler documentation and the template ( mytemplates/libvirt/libvirtxml.tmpl) should be adapted to read:

<interface type='bridge'>
   <source bridge='br0'/>
</interface>

 The interface type should also be changed to 'bridge' instead of network.

Further installing a more complete PERL (I added perl-debug) will remove the PERL error messages the vmbuilder script spawns.

Anyway, I got my KVM server running. Thank you.