If either you or your spouse is not a Finnish citizen, then you will have trouble adopting a dog from the Finnish organisations. Reason being that the adoption contracts state that the dog does not belong to you, but it belongs permanently to the organisation i.e. you can not move out of the country and take the dog with you and you also can not give the dog away to somebody else. This is a fairly standard adoption contract in almost any western country, nothing special regarding Finland. Estonia still being similar to a third-world country, they take a very lax view on most things - not too long ago, somebody shipped a horse from Estonia to Finland inside a metal shipping container and it died from the heat.
Other than that, about 3-4 years ago we adopted two very wonderful dogs from this organisation: http://www.espanjankatukoirat.com
The adoption fee is 450 EUR, and that covers the costs of transportation from Spain, neutering / spaying, initial immunisations, health check, dog's passport, and microchip.
Where to buy? Where can I find? How do I? Getting started.