Assuming your Ameraucanas are true, blue egg laying Ameraucanas rather than Easter Eggers, you can cross them with any of the chocolate egg laying breeds (Marans, Welsummers, Barnevelders, Penedescencas) and get Olive Eggers, which are a very popular variety of Easter Egger.
I liked crossing my EE with brown leghorns. Similar to the now popular super blue egg layers. The EE, or in your case Ameraucana, contributed the colored eggs and the Leghorn blood boosted egg size and production. I used the brown Leghorns simply as personal preference as I don't care for white birds.