I think you'll find, on nearly every electrical device, that once you're past the power lead in the wall and past the transformer inside the device(the amp in this case), everything is the same.
It's like a multi-country shaver or whatever.
you flick the switch which changes the way the transformer delivers the power to the electronics inside...but the electronics themselves don't change....
Your guitar will be sweet as!
I've been thinking about doing the same thing, and i wouldn't even be worried about the power issue.
I want a Gison too but they are so damn expensive....and $100-$150 delivery isn't too bad when you get em hundreds cheaper than here.