Oh, there's also Jumbo quail. I've seen some listings say they can get theirs up to 1.5+ pounds easy. But I think you need an aviary. Mainly thinking of fastest turn-out.
Though, fastest turn out is trading with someone else who've put the time and feed in to their poultry who are sick of that type or that particular animal (as in, they're a jerk and need to go.) so even if you stick to chickens, still try to keep in the back of your mind filling a niche no one else does.
I have some 2-3 year old ducks that I never would have raised. But I am happy to be able to try eating 2-3 year old duck meat.