Sabers: I'd go with Kenobi. There's nothing that Vader has that can break through his Soresu and within head canon ROTS Kenobi should have a physical strength advantage against Vader.
Force: While most would say Vader I'm not opposed to the idea of Kenobi matching him if he went all out but yeah Vader has it.
All out, it's close but I'm leaning Kenobi especially since this is Vader before his prime.