There are a few schools of thought about how the Phoenix looked... but the most popular one is that of a Great Heron (Long Necked Goose type). They have a huge wingspan, and their wings are not unlike those of an Eagle. You may be able to morph the eagle into what you want... but I'd recomdend starting from scratch. Maybe with the Posable Wings located here. Too, there is another school which sees it as a Bird of Prey, but that's less popular