Guilty Gear 2? Really? Potential quality of the game aside, I'm fascinated that it's your 'one game' for the 360.

I think Croyles is from Germany, he should be able to give you info on power grids and whatnot. But as far as I know, all of the PAL systems are the same, so I would assume the voltages would be identical. If not, there are voltage converters you can use. I had to use one when I went to Australia earlier this year.

Languages: I know for sure that the 360 lets you choose what language you want, and I'm 90% certain the PS3 does as well. Not too sure about the Wii, but it is more important for the software to be in the right language.