Good choice with the blackish background as well, Cavalier. The khorne red actually looks bright. Do you strip the models, then repaint them, or just give them another, very thin, coat.
Looking forward to seeing your style on those jumping Chaos models. We know you'll do them justice.
Personally, I've always thought the jump packs look top heavy with the running legs. I swap them with Grey Hunter torsos. The JP troop look balanced in their fighting stances, and the GH's look like their charging. Especially with the snarling faces. With your job and hoppy, mate, you must do nothing but eat, sleep and paint.