To see what can be done, you need to provide some more details about your environment.
- which vCenter version(s) do you use?
- which ESX/ESXi host version do you use?
- Which licenses (vCenter Server and ESX/ESXi hosts) are in use?
- are all hosts able to access the same storage?
In the best case you could simply add the hosts to the same vCenter Server and migrate the VMs online (or offline) without the need for Converter, which btw. would result in the need of network reconfiguration for the VMs due to UUID/MAC address changes.
André