A:Answer I'm not sure so do not quote me on this, but I think that the PSU (the power supply unit) supports both voltages and changes between them automatically, without the need of a voltage selector switch, all you need is an external adapter to fit the power cable into the wall socket, when you do that, you should be good to go.
Yes I am an owner of the same machine the Alienware Aurora R7, and I live outside the US where the power supply is around 240 v on average, and I am currently in the same dilemma.