I've never done this kind of thing, but I have brothers who have led such groups. They found that dividing the group into cooking groups was the best solution. So like 3-4 people would all be in a designated cooking group that shared a stove and pot for the entire trip. The easiest way to make that simple is for people to have meals that only require hot water (freeze dried dinners, mashed potatoes, oatmeal, etc.). So they boil up one big pot of water, prepare their meals, then everyone can pretty much eat together and at the same time without having to wait for the stove to become available or having to carry some huge thing.
As to the equipment, I'd say just a typical backpacking stove like a Jet Boil or Pocket Rocket and maybe a 1-2 liter pot per group.
