I used the CBT's from Sun to finish my SysAdmin and NetAdmin. For Solaris 9. Though in hindsight I don't think that the training material that I got was all that great. I felt that they were not very well put together. Considering that each CD was $1000 Canadian.
I would instead recommend that you take a look at docs.sun.com
in detail for the version of Solaris that you are trying to certify on. (This site is by far the best that I have found) When I say in detail, I mean read through absolutely all the documentation particularly paying attention to the commands section. The SolariAdmin tests 1 & 2 are going to test you very heavily on commands & there options, file system structure & and hardware as well (i.e. inodes & hardlinks)
Note: you will also be tested on your knowledge of the OpenBoot prompt as well. So having access to an older SPARCstation would be an asset. I did my training on an ultra 1 with 200mbs of ram. But you should be able to use either a sparc 4,5,10 or 20 as long as you have enough ram. If for some reason you are not able to get your hands on a Sparc an x86 PC will do for the OS part but again you will need to memorize and understand the openboot prompt commands
Hope this helps you