Would suggest you go through the hall of fame for SCBCD exams to get an idea of the questions you have in your mind.
These were some common questions which would come to everyone's mind before choosing a certification, so it should also be answered in some previous posts itself.
I am not the right person as I do duplicate posts some times
Just my two cents !!
Personally, I would suggest you to go for EJB 3.0. And, there is no full fledged book for EJB 3.0. I found most of them suggest, Orielly EJB 5th editionApress for Persistence API
Again I would advice you to go through hall of fame.