The GB4000 and the SR4 amplifier both come with a "Switching Power Supply" that will automatically detect the voltage in your location and adjust accordingly. The MOPA Amplifier will be configured at the factory for the voltage at your location.
So, if you are ordering a MOPA Amplifier, please make sure to tell us if you will be taking the machine to a location other than the shipping address that you give to us during the order process so that we can configure your new MOPA correctly.
The only adapter you should need would be a plug adapter to change from the US style plugs included with your new machine to the shape of plugs used in your location.
Please note that any import duties or taxes will be paid by the recipient. We don't have specific information on import duties or taxes charged by different countries.