John Constantine:Ewan McGregor
While fan-favorite casting Colin Farrell would be perfectly acceptable by me, I have to say I'm a bit biased towards McGregor for the part. They'd both be great, but since Disney seems foolishly uninterested in a Kenobi spinoff, I'm hoping Ewan can get himself another franchise to head up. He brings just the right set of skills to the table: Able to seriously handle dark material while maintaining a memorable charm and wit. He has all the charisma needed to lead this mystical band of misfits. (Also, here's to hoping the more lenient world of cinema allows Constantine his chain-smoking ways, because McGregor also has good expirience playing a drug addict)
Zatanna:Ruth Negga
Amy Acker continues to be my top pick for Zatanna, but for this I'm going with the rumor that they want a non-white actress in the role. For that, then I pick Ruth Negga, a very talented actress who is no stranger to comic book properties, on television, at least. As the presumable co-lead, Negga brings enough charm, charisma, and energy to rival McGregor's Constantine. And as an early Oscar frontrunner following "Loving" opening at Cannes, she'd be yet another in a long list of high caliber talent picked up by the DCEU.
Etrigan the Demon:Woody Harrelson
Etrigan is certainly a tough one to pull off, but he's key to the team. The whole "talking in rhymes" thing could easily come off as silly, no matter how physically scary Etrigan himself is. But in the hands of the right director and actor, he easily can steal the show. Harrelson can pull off both funny and intensely intimidating at once, and has more than enough personality to make Etrigan the next in a line of characters like Rocket Raccoon that no one thought would ever work.
Deadman:Adrien Brody
Deadman is a complicated character, who can both be very fun and angst-driven. Adrien Brody is a very talented actor who's been lacking for a major role lately. Deadman is just the type of character to get him his comeback. Like Etrigan, Boston Brand is a major potential scene stealer, full of both humor and pathos. Brody has more than enough talent to pull him off memorably.
Madame Xanadu:Sarah Shahi
I'll admit, out of all the rumored members of JLD/Shadowpact, Xanadu is the one I know least about. But from what I've managed to figure out, Shahi meets the qualifications to a tee. Exotic, and capable of being both mysterious and badass when needed, she could effortlessly slip into the role of the morally questionable mystic.
Swamp Thing:Clark Peters
Now, I know everyone and their best freind's uncle expets Ron Perlman in this part, and I certainly couldn't complain if he got it, but I'm going to go a different route. Peters has a great voice, the type that can calm you and terrify you at the same time. It;s the type of voice that needs to be coming from Swamp Thing's mouth. Speaking of which, I'm hoping they go the motion-capture route here. Killer Croc's prosthetics & makeup turned out very nice, but with Swamp Thing, I think it's definitely for the best they animate him. As far as CGI has come these days, if they can make Swamp Thing as realistic as the animals in the Jungle Book, it would truely be a magical thing.
Anton Arcane:John Nolan
Arcane might not be my first choice for the villain here, but I'll stick with the rumor. He's certainly a big enough threat to take on the whole team, and would be quite the memorable antagonist. John Nolan recently came to light as a splendid mastermind villain on Person of Interest. Though it's too late for him to be Magneto (I'd have gladly traded out McKellan for him) he'd make a truely menacing fit for Arcane.