I am a chaos man as well. I always wanted CSM's from the start. I branched out into nids for a while but they did not hold my interest. In the end my second army became guard, done up as traitors. With the more recent developments they can play as the chaos cultists or as part of an allied force. Gave me exactly what I wanted. Two armies that would play well as allies or opponents. Even though I have not played or worked on my armies in a long time they are still the ideal combination for me.