When it comes to the height, a freestanding dry stone wall is quite a challenge... it also requires reinforcement anchored in the foundation that runs up through the wall, as well as, if possible, anchoring to the sides with concreted piles or to the house wall. How about a gabion fence (basically 2 fixed fence panels with a hand-width gap filled with stones)? Or a solid wooden fence, such as the concrete/wood fence from Lind Beton.