I think your best bet would be to contact a few online nurseries directly, to see if they will send seeds to you. Most people here start with plants, or cuttings I think.
The risk you will take is whether you are allowed to import the seeds into Sweden. First check with your department of agriculture about that because even if you buy seeds and get them sent to you, they may be stopped by your customs people on that end. That would be a shame, after you've paid for seeds and shipping.
Here's a link to a big commercial seller's Coleus page. Across the top bar at right there's a "contact us" link where you can e-mail them and ask if they will send you seeds. Most online sellers have this feature.
http://www.burpee.com/flowers/...
