Ix nay on Hawgirl, man. You sound too grounded in the cartoon, lol. I'd rather see Hawkman and Hawkgirl, like the comics, or the Atom or Green Arrow in substitute for either of them.
But seriously tho, I don't really want to see Hawkgirl in a movie (the first JLA movie anyway). She's the epitome of a second stringer. It'd be like having Supergirl or Batgirl in substitute for Superman or Batman. And I'd hope that the movie would be more faithful to the comics than the cartoon, it shouldn't be just be a live action adaptation of the cartoon. The cartoon was good, but they meshed a lot of characters together that, IMO, wasn't really necessary (namely Flash, who had Wally West's name and appearance (red hair, green eyes), Barry Allen's story, and Bart Allen's personality, and GL, who had a lot of Hal Jordan's story elements, such as his GL status and villains) and tweaked a couple things that didn't need tweaking. Bottom line; whoever makes the movie should be influenced by more than just the cartoon, they need to dig deep into the JLA comics.
But as far as things like personality and character relationship/interaction go, this is what I'd like to see:
Superman - the strongest and possibly most powerful member of the team, the leader and face of the League
Batman - the smartest member on the team, the detective, strategist, and tactician, he's the League's thinking man, also a leader, but is the most reclusive of the League when it comes to public affairs
Wonder Woman - a woman's perspective on things, she also serves as the league's diplomat, but is also a warrioress
Flash - the more humorous of the bunch (tho NOT the token comedy relief or a moron, like the JLU cartoon made him), he is happy to be included, and provides a scientific perspective on things (being a forensic scientist), he finds WW attractive (who doesn't?
), but his college GF, Iris, is his girl at heart (this relationship could be played remniscent of his relationship with Black Canary in JLA: Year One)
Green Lantern - the interstellar hero, if it's extraterrestrial, chances are, he's dealt with it before. He provides a straight laced, military/cop perspective on how to deal with things (being a jet jockey and GL) but is also a bit of a daredevil and showoff
Martian Manhunter - not the smartest, but the wisest of the League, provides a philosophical perspective on things, the league is his only sense of family
Aquaman - king of atlantis, he's there should something important occur underwater (fat chance heheh), seriously tho, he's a king, and is somewhat pompous and pontificate, he's interested in what's best for his people but when the chips are down, he's a team player as well
^ That's pretty much what I'd like to see character wise.