I recall a shot from TROS where Ben is standing on the edge of the Death Star wreckage, very reminiscent to Wanderer above the Sea of Fog, right before Han appear to him. You could possibly use that shot, and have him standing on that cliff where Luke faded away. You could have Kylo looking at the Ach-To sunset like Luke did, while Rey looks at the sunset on Tatooine (or on a different planet), and maybe there is an applied Force bond between them as they look at each other from across the stars.

EDIT: Would you prefer an ending with Ben in exile? How would you feel about it ending with Ben and Rey together?