I didn't do Spesh but I bought the exampro guides for Biology, Methods and Accounting.
Personally I think previous SACs from your school will be the best "study tool" to work through before your SACs as they will most likely be on a similar level of difficulty with similar questions. I worked through the Exampro guides about a month before my exams as a revision tool as I tend to forget things quickly, I think it's extremely effective in testing what areas you are familiar with and what areas you need to improve on, hence targeting specific areas, saving you a crap load of time going over things that you already know.
However, it is up to you how you want to utilise it. Everyone learns differently and those extra topic tests from Exampro may boost your SACs tremendously.
Good luck
