Go for
SCJD if you like design+programming very much;
And the others (SCBCD, SCWCD) are more like the
test on memorization works.
Normally we follow the path like SCJP->SCWCD/SCBCD->SCJD/SCEA.
Of course, pls correct me if i just simply make the above assumption.
For study materials, you'll find lots of useful advices from this forum.
As you will find SCWCD-Exam-Study-Kit appears frequently...
