Hi James
You can automate the xenserver build by using approach described by Tim Mackey at http://xenserver.org...r-at-scale.html
We use it internally to build all the servers and apply the upgrades. Once servers are build you still have to join them to the cluster and add to cloud platform. It takes about 30 min for us to build a cluster of 10 servers.
Good luck.
Best regards
Yuri






