Actually, the cheapest option may be just getting an adapter for your current Volt EVSE. It's been shown that those EVSEs work on 240v as well as 120v, which makes sense since they were likely shipped to Europe for the Opel Ampera.

It's not a standard (safe) adapter since it's meant to plug a 120v plug into a 240v outlet, but it's perfectly safe when using it for equipment designed for both voltages.

Otherwise, I've always like the flexibility of the TurboCord