I always thought you could turn the six episode saga into three episodes, by taking each episode of the OT, intercut flashbacks from the Prequels (Godfather II style), telling Luke's story and Anakin's story simultaneously, and depending on what you reveal and when you reveal it, you never have to lose any of the surprises (Vader as father, Leia as sister, etc.). This is great because you only keep the good parts of the Prequels and don't have to deal with Jar-Jar or anything else you don't want to.

This is very close to what you're doing, so I'm very interested to see what you come out with, TDH.

The flashback of Obi-Wan and Anakin actually fighting Vader though is something I had never even considered, and it's a great idea to sort of throw the audience off as they're seeing what Luke imagines. It's gonna be tough to synchronize everything on a thematic and emotional level, but by focusing on Luke, you've probably freed yourself up a little. If it works, this could be a really amazing project.