http://www.themapcentre.com/acatalog/Online_Catalogue_IGN_Blue_Walking_Maps_57.html

1:25000 scale makes them the same as the orange OS maps. The mapping is close to, but quite up to, OS standards. Once you have the map you want you need to go over it, square by square, with a highlighter pen and find all the dolmens (which look like tiny picnic tables) and menhirs (tiny isosceles triangles), otherwise you'll end up missing them once you're out and about....

Enjoy