The most suitable is Kathy and Bert's HF
EJB. You might also consider to read some books that are NOT target for the exam, but still they are good reference books, like Enterprise JavaBean 3rd edition, Mastering EJB 2nd edition...
Also, please read MZ's notes as well, he did prepare good revision notes for us to revise the exam.
Nick
SCJP 1.2, OCP 9i DBA, SCWCD 1.3, SCJP 1.4 (SAI), SCJD 1.4, SCWCD 1.4 (Beta), ICED (IBM 287, IBM 484, IBM 486), SCMAD 1.0 (Beta), SCBCD 1.3, ICSD (IBM 288), ICDBA (IBM 700, IBM 701), SCDJWS, ICSD (IBM 348), OCP 10g DBA (Beta), SCJP 5.0 (Beta), SCJA 1.0 (Beta), MCP(70-270), SCBCD 5.0 (Beta), SCJP 6.0, SCEA for JEE5 (in progress)