I second the tagine with preserved lemons and olive idea, maybe served with chive batbout bread.
Or maybe a chicken tandoori with a yogurt-mint cardamom dip, arugula, and toasted naan strip?
I have prepared coq au vin for 130 people before, it was VERY labor intensive. Lots of components have to be prepared separately. Plus, peeling pearl onions one by one is never fun.
If you have sous-vide equipment, ll you'd have to do is toss in the spices, the skinless raw chicken and onion in the pouches(drumstick/thigh meat highly recommended), and preserved lemon and olives if you go for the tagine. Vacuum pack and drop the pouches in boiling water for 10 seconds to kill surface bacteria. Then cook them low and slow at 140 degrees for 12 hours. One hour before the event starts, you collect the liquid from the pouches and reduce it to a thick consistency, then put your chicken in the oven at 200 degrees to develop some succulent goodness without risking to burn it. Serve topped with the reduction, directly from the oven.