Sapins: I remember that you live in France, and the picture of your beautiful area that you posted some time ago.
As most of the members of this forum are based in the UK, I doubt that we can help. From my wide travels in France I cannot recall any especially good locations for currency exchange.
I suggest you ask around locally, especially with any ex-pats in your area. As you may know, the rate of exchange for £ to € is very low at present. I got 1.20€/£ this week, which was as good as I could find locally.
Sapins. I lived in the Netherlands for about 10 years. I had a Euro bank account there and a sterling account in the uk, and found it best to send money from one to the other via the bank's "Swift" or similar system. Then you can have bank ATN cards in both countries. I also have an account in Australia for similar reasons.