Hal Jordan: Matt Damon
Why: The Hal we know from the comics is around Batman's age. Plus, the Hal I envision would be the drill sergeant of the group(with some wisecracks thrown in)
John Stewart:Trevante Rhodes
Why: Alright, I understand a lot of people want Idris Elba, Tyrese, Sterling K. Brown, and the lot for Stewart. However, someone needs to play the ranbunctious youngster to Hal's weathered self, so enter Trevante Rhodes, who starred in this year's Moonlight(also, this is my childhood, John is my lantern, why would I miscast?)
Guy Gardner: Seann William Scott
Why: Scott plays rough and rowdy well, which is Guy to a tee.
Kyle Rayner:Jack Huston
Why: Rounding out our main lanterns is the newest member of the Huston acting dynasty, who is best known for playing Richard Harrow on Boardwalk Empire. He has the acting chops to pull the role off, as well as the youthful face to pair up with the younger John Stewart.
Sinestro: Hugo Weaving
Why: Yes, I want Mark Strong back. However, Hugo Weaving isn't a bad replacement.
Bonus: Tomar Re: Kenneth Branagh
Why: How awesome would it be having Tomar Re helping Hal out with these youngsters?
Director: Duncan Jones
Notable work:Moon, Source Code
Why it would work: The dude makes great science-based sci-fi. Bottom line.
Well, that it guys(or gals). Hope you enjoy that, and leave anything you have to say in the comments section.