In my view one should go for 1.4 Exam. As the 1.5 is not yet fully developed by Sun. As thier is only S.E Developer Exam available after SCJP. But the other development as EE and ME are all working on 1.4 base.
Kamlesh
Be oN edGE SCJP 1.4, on edGE for SCWCD 1.4