Aren't Smarties more like m&m's? I can't remember, don't buy much candy anymore.
I think US expats have it easier to find treats from home. Here many grocery stores have a shelf of Murican products, so you can get your Reese's peanutbutter cups and whatnots. Scandinavians have it quite easy as well, you can just go to any Ikea in the world and find some of the things you miss from home like lingonberry jam or glögg. One thing you can also probably find anywhere in the world is a Middle Eastern or Asian store that imports directly.
This is going even further off topic, but I heard a funny story about a woman who was furious in the produce isle, screaming at the staff because they didn't have domestically grown bananas. I'd like to see a banana tree that can manage in a Finnish climate.