I think it's funny the hodgepodge of different accessories for the Impreza that are out there, but there's not one location that has everything available for it. The most common thing that I've seen is that the US-package Sport version has painted 17 inch alloys and roof rails that aren't available on other international versions. However, there are International versions that have side-mirror turn signal lights, HIDs, and non-sport versions of the 4 and 5 door variants with the side skirt rocker panels.
It makes me want to order some parts internationally to put on my Impreza. I'd love the side-skirts on my non-Sport Impreza and those side-mirror turn signals are just cool to me.