I still think the best way to do this was retain the original spirits, but after Luke acknowledges them, have ALL THREE of them appear as their PT selves. And if you want to go for the fairy-tale ending, have Padme appear at young Anakin's side. I mean really, how happy an ending is it when the love of the main character's life, not to mention the mother of the OT's greatest heroes, is nowhere to be found at the big ending celebration, apparently lost forever to the afterlife. Kind of takes the cheer out of things, huh?