I just found this video this morning. I don’t know if anyone here has seen it, but user Idkartist added ghosts of both Ben and Anakin to the end. The effect looks amazing, especially the footage they used of Adam Driver. The only thing I’d do differently in it is to have him in Jedi robes instead of his Kylo Ren attire.
I don’t know if Anakin is really necessary for the scene. He would be more like a bonus.
Kylo, on the other hand has to be there. I second having him with a lighter robe (unlike Anakin, Kylo’s dark costume design has always been associated to his evil phase).