I'd wait 'til after E3, just because the price might drop. I can't see that you lose anything by waiting a few days either way.
Whether the power will be compatible or not depends on where you're at. In the US I don't think it will be a problem, but if you're in Europe or Australia you'll need a new cable or a power converter.
I don't have any clue what you mean by 110 and 220 versions, but oh well...
By the way, there are two limited edition colors for the SP so far. There's a Pearl White SP that comes with FFTA, and a Flame Orange SP (Pokécenter exclusive) with Achamo/Torchic emblazened on the front. They're both exclusive to Japan for now.