I decided to ask around and find some adult chickens. I was looking for 2 or 3, but I got lucky and got 9 hens.
1 Barred Rock, 1 Golden Wyandotte, 1 Buff Orpington, a few that appear to be Arucanas, and 1 Rhode Island Red.
At first, all of them were fighting the rooster and bantam to find pecking order, but everyone seems more settled today.
Also today: I got an egg!! :)