If you are moving to a new location, then, it would be better to set the servers you want to virtualize in the new location while the old servers are still in the old location. Move all the data to the new location and set it up with the same Names and IPs (not in the domain). Then when you move, move the new data (since the last restore)to the virtual servers and then remove the servers from the domain (all servers that you virtualized), move all equipment to the new location. finally rejoin all vitual servers to the domain. This will minimize your down time. You could also move then do the virtualization in steps by servers.