Hi,
The FindByUUID() as mentioned in the documentation (http://pubs.vmware.com/vsphere50/index.jsp?topic=%2Fcom.vmware.wssdk.apiref.doc_50%2Fvim.SearchIndex...) only supports looking up Virtual Machines and/or Hosts, Template lookup is not possible. What you could store is the MoRef ID, this will be the same whether the object is a VM or VM Template, there just one property that is boolean that determines whether a VM is a template or not, other than that, everything else is the same. This assumes that your templates are persisted and if they do change, you should update your external database with the proper MoRef ID and then you can create a Managed Object Ref based on the MoRef ID to quickly be able to perform an action on the template without having to search through your entire vSphere Inventory.
Just as an FYI, UUID is not guaranteed to be unique, you should use the instanceUUID which is guaranteed to be unique for a given vCenter Server instance.
