This takes place in the Man of Steel universe, so the whole cast is returning. Original idea... No. But whatever, it was it is, I liked the movie and I'd love for it to connect, which it probably will.
Philip Winchester as Batman/Bruce Wayne: I've seen some of his stuff, I know he's been a popular pick for Aquaman, but I think there are better roles for Philip Winchester (Like Daredevil as well) and better acts to play Aquaman. Also he's tall, which I know is a big deal for you Mr. DDD, and he kind of has a Bat-chin.
Zachary Levi as Flash/Barry Allen: Yes he's a bit tall for the role, but if they can CGI Ralph Phinease nose off they can make Zachary not look so tall. Anyway, his role on Chuck is of course what made me think he'd fit Barry. Barry is the "Average Jo" of the JLA, he's not necessarily serious, but he's not a comedian either, he's just a normal smart guy. I think Zachary could make Barry lovable and a relatable character.
OR...
John Krasinski as Flash/Barry Allen. Everything a listed above but with a bit more confidence.
Armie Hammer as Green Lantern/Hal Jordan. I feel like this pick is going receive a little bit of backlash. I stand by it though, I've seen some of his work and I see him as Hal, not quite so witty as with Ryan Reynolds but not super (ha) serious. Hal would pretty much butt heads with everyone but Barry his best bud. I keep hearing that Armie is to much of a "Pretty boy" have you seen Heath Ledger? Heath Ledger WAS a pretty boy before being cast as Joker. Make up can do a lot for a person.
Idris Elba as Green Lantern/John Stewart. Now this I KNOW is not original. And I will probably get backlash, but whatever, don't fix what is not broke. Assuming JLA follows the tone of Man of Steel, how he would play John would fit the tone. Justice League needs a really strong well put together cast to top Avengers. Now, why two Green Lanterns? Honestly, I have no good reason, but lets use that as an aspect of the film, Hal and John can butt heads. John would mostly be in space during the movie, coming in at the end when he finds out what is going on.
Bridget Reagan as Wonder Woman/Diana Prince. Not super original, but she fits great! I used to watch Legend of the Seeker and she was really good in it so, why not? As for WW costume, I'd like her to start in her pre-new 52 one, maybe she can have the New 52 suit in JLA 2. On her powers, she should be able to go to toe-to-toe with Bats and Supes. She has combat skills, not quite as good as Batman, but good enough to hold her own, her super strength giving her the upper hand at least when they first meet and Batman doesn't know her limits. The same for Supes but reversed, she's not as strong as him but her combat skills give her the upper hand at least once.
Michael B. Jordan as Vic Stone. Vic is not really "Cyborg" in the movie, he does become Cyborg but he's not really a superhero yet, he's lost and confused by his new body and helps pretty much because he has to. Again not original, but oh well, he fits, I have no one else, if you guys have suggestions please tell me!
Ralph Fiennes as Lex Luthor morphed with Brainiac. Remember in Justice League Unlimited when Lex morphed with Brainiac? Yeah that was awesome. So let's do that again! I really thought that episodes was awesome, and it posed a big enough threat that could unite the JLA but not ripping off Avengers, Lex could fine the Brainiac tech in the rubble left in Supes vs. Zod's fight. He takes it and tries to rebuild it, Cadmus comes barging in, there is an explosion (that creates Cyborg) and boom the two are mixed. On Ralph, I've seen him cast as both characters, now he can play both.
Jon Glaser as G. Gordon Godfrey. I forgot to add him to the cast last night, so here he is! I saw Jon on Parks and Recreation, and his character is one annoying human being, like G. Gordon. Plus I have not seen anyone cast him as the character so at least its original. G. Gordon would spew hate about meta humans at the beginning of the film and then spew hate about the JLA forming a team, saying its a plan to over take humans.
Cameos from:
Jake Abel or Liam Hemsworth as Wally West
Joel Courtney as Dick Grayson (in the Flying Graysons still)
Charlie Hunnam as Oliver Queen
Yvonne Strahoski as Dinah Lance
Anna Kendrick as Iris Allen
All the cameos would be watching Iris Allen report on the Brainiac Lex attack, Dick with the Flying Circus, Wally just at his house, Oliver and Dinah at Oliver's mansion. Oliver would go to suit up and Dinah would tell him to stop and wait to see how it goes.
And that is my cast! I hope you enjoyed it, it's 12:38 AM, I'm tired, so if my explanations ramble, I'm sorry. I'm very tired and already talkative for the most part. I may update this tomorrow with a better explanation of the story, but for now GOODNIGHT! (Or morning technically--.../?';';
Have a MARVELous God Blessed day!
--SAT