This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I guess you are referring to OCAJ 5/6 as OCAJP 6 doesn't exist. Or do you mean OCPJP 6?
If you are a java programmer (developer) just go for OCPJP 6 (1 exam) or OCPJP 7 (if you don't have any Oracle/Sun java programmer certification yet, you'll have to pass 2 exams, otherwise just the upgrade exam). The OCAJ 5/6 certification has very little (none) added value for a programmer/developer.
I was going to go for SCJP6 first, but damned if I'm not stupid as hell. Kind of humbling trying to take these certification mock tests. If you're starting from scratch, it looks like the OCAJP7 is the way to go since they are sticking it to you for 2 tests up to OCP level anyway. I am scoring a good amount higher on the OCA mock tests than the stuff in the K&B book which looks to be way more involved...