[hibernate-dev] What is the easiest and safest way to customize Hiberate for other entity mode?

Hi all: I'm developing SDO(Service Data Object) implementation, and when I wanna persist them Hibernate is the first one came to my mind. I tried it's dynamic-map mode, but that's not what i expected, I want to customize Hibernate to make it full SDO support. For the sake of safety, the minimal classes needed to be overrided or changed, the better. Any hibernate guru can show me the right way? very thankful!