When it comes to authentic Greek Yogurt and cheese this is the place I recommend.

These are people that love what they do and see their work as a mission. These two things are the best ingredients to all kind of recipes.
They have their own milk production and so they do everything themselves from scratch.
While most people are used to the tastes of cow-milk products, the authentic Greek recipes are made of goat and sheep milk.
They do offer products made of cow milk, but I would suggest to rather try the authentic versions. When you get used to it, you won’t like to get back again.

Apart from milk products they also offer a variety of traditional Greek products, so I do think their shops are worth a visit anyway.

In Kalamata there are two shops, one in the centre of the city and one at the seafront.