I'm thinking of taking the Solaris 10 exams, and never taken Sun's exams before. What kind of home lab is adequate for preparation? Would a couple of Sun Blade 100's and some USB storage be sufficient?
You should get more practise. Purchase solaris 10 book or go through some online tutorials. It should be adequate for you to get through 
They have SysAdmin documents which cover all of the subjects the exams can cover. That with 1 or 2 test systems should get you enough to pass. I took the SCSA for Solaris 10 about 2 years ago and got passed the tests on the first try. I used docs.sun.com, some test systems, and a retail book designed to teach the exam; the book was the least helpful.
I can share ..write to me to