JDO Implementations like Hibernate
Well, Hibernate is not a JDO implementation but that's the sort of thing I'd suggest. Any good ORM technology will be better than Entity Beans.
BMP is probably your only option if you want beans spaning multiple tables (thoug has I remember, there are venodor-specific CMP implementations which can handle multitable CMP - I'm not sure though, someone might shout me about that).