You should use the persistence-specification from EJB3 because then you are independent from the specific persistence-framework of the J2EE-server. For example javax.persistence.Entity instead of org.hibernate.annotations.Entity. The J2EE Server has to manage this specification by a concrete framework(for example Hibernate).
To bound the jars bind a server runtime in the properties of your ejb-project and you include all jars from the JBoss. In eclipse you bind the server runtime by going to properties-of-project -> Java Build Path -> Libraries -> Add Library -> Server Runtime -> and the select the defined server.