OK this place in Turku could suit you:
http://www.partiovaruste.fi/
You can see the address on the right, including a picture of the shop front.
Copy/Past this "Lantinen Pitkakatu 13 turku" into googlemaps.
They say this:
Laskimme, että sesongin vaihdon myötä saimme Turun liikkeeseen esille yli 30 metriä reppuja ja rinkkoja: kolmessa tasossa!
Which means they have over 30m of rucksacks and backpacks (on 3 levels), so you won't be short of choice.
On this link are further links to their brands:
http://www.partiovaruste.fi/ajankohtaista/2008/huhti/kymmenia-metreja-reppuja/
