Honestly he's a no-go for me on playing Dick. He just has something about him distinctly NOT Dick Grayson. If I had to pick an already famous actor, it would be Milo Ventimiglia (Peter Petrelli on Heroes.) I think he looks the part, more so than "Davis" here. I'm not sure why but I just can't see it. Milo has also mentioned that he would be interested in playing the character.

If I had to choose though it would be someone who is a gymnast that resembles him and could do the stunts himself. I think when stunts are done mostly, or completely, by the actor the movie would feel more "real."