Sounds similiar to POS (Point Of Sales) setups.
You are in a serious production environment, therefore it would be suicide not to use vCenter to control your ESXi hosts, which will answer all your needs for your stuff that "are remotely set up".
You would certainly benefit by having one "golden template" that you can clone for each vm toll gantry.
The "golden template" can either be a powered down VM or saved as a single file .ova (similar to .iso or .ghs).
Good backup software like Veritas Backup Exec will backup each VM directly from the vCenter. A lot of folks think you have to back up the actual raid disks for the datastore, but it's sufficient to simply grab just the VMs.
There's no need to ever muck into the datastore or any of its directories. vCenter will let you do everything from a web interface and right mouse button clicks.
Don't get caught up into building some external datastore. If you don't know where to start, using ESXi for a datastore is great for most.
The above setup is so reliable, you will probably experience less or no more crashing at all without the use of HA, which you can always decide to upgrade to later.
Existing physical boxes can be turned into vms one by one. I've made screenshots if you'd like to see how the process goes:
Re: P2V Windows XP
