Since SCJP 1.5 is the latest one , i prefer to go for it. There are even other criterias you should consider, like the platform or version in which you are working now, etc etc . You can refer to the other
thread by Bert Bates regarding the scheduled release of 1.5 books. The time of preparation varies from person to person.
Thanks & regards, Srini
MCP, SCJP-1.4, NCFM (Financial Markets), Oracle 9i - SQL ( 1Z0-007 ), ITIL Certified