Hi Christian-
Thanks for your quick reply. I can confirm that I was able to launch a machine from the Marketplace and access via the HTTP Guacamole interface and have a little play around. Thanks!
Regarding the build your own, our lab runs primarily RHEL, so I will need to try and find a desktop running Ubuntu. I originally tried my Mac laptop but got into some issues regarding one of the rsync commands. In the meantime, I can wait until the new build your own scripts are available.

Many thanks for your help.
Dave