I would use Typhus, but he's one of my favorite Chaos models...plus he goes so well with DG and he's a lord AND sorceror
I'd also lose the Dread. They got nerfed in this last codex, but not being able to go into assault frenzy, and that lascannon could be bad for you...
I'd also nix the Undivided marines for more DG...but that's me.
Heavy choices are good...and then there's the Predator to consider...