Alexa isn't tall enough but Morena would have been amazing. I am curious as to what Joss Whedon's version of Wonder Woman would have been. However, WB turning him down led to Whedon going to Marvel and making the Avengers, so it all worked out in the end.
Um, Alexa Davalos and Morena Baccarin are both 5'7, which is above average height for a female. Now, they're still shorter than Gal Gadot's 5'10, but they're still plenty tall, comparatively speaking.