I'm guessing it would be Barry with a lot of Wally's personality.
Which is fucked up, if there's one thing I hate that Johns did it's to bring Barry back. Barry died an amazing hero's death in the 80's and it allowed Wally to grow up and eventually become the hero we all know and loved.
Heck he was the best thing in the Justice league cartoon, he's the guy a majority of the casual audience knows.
And now he basically doesn't exist. I know I shouldn't constantly complain about it but he's my flash. I like Barry but Wally will always be my Flash. I go back issue hunting for the Waid run when I can. It's just how it is.
Transplanting Wally's personality to Barry in a movie would be super fucked up.