|Color scheme for my traitor guard: crimson robes with bronze armor.|
I already have enough models to field a 1000 point traitor guard force
-2 Russ Variants
-60 Infantry, with a mixture of GW Cadians and Wargames Foundry Shock Troops. Heads are Fallen Legionaries from Maxmini.
As far as a background justification for IG allies, I'd like to point out the difference in the Gaunts Ghosts books between fanatical and organized Cutlist groups like the Infardi versus the military professionalism of the Blood Pact and Sons of Sek. I can easily see the IG rules reflecting the better equipment and training of the Blood Pact, while Cultists from the Chaos Codex reflecting the more religious members of a Chaos Lord's forces.
So my army could consist of the following:
Chaos: Primary Force
-1 Chaos HQ
-2+ Chaos Cultist Squads
-Psyker Battle Squad