Hi,
I spent a year and half in Germany with my ibook without any problems. Macs handle 110 and 220 W. The ipods too.
The only difference between countries, (I think) are the keyboard layout. If you are in the U.S. they sell the standard american keyboard and the spanish keyboard. If I were you, I would ask either at best buy or at an apple store for the keyboard for spanish speakers. Besides this letter "ñ" that you may not need, it is somewhat easier to write the "Umlaut" for letters like: "ä, ö, ü" and also the "ç" in case you may need it as well. Of course one can do some adaptations for the "ß".
I hope this helps a bit, kind regards,
igmolinav.
P.S. Wenn ich weiter hilfen kann, bitte schreib mir eine e-mail an:
igmolinav@yahoo.de