Hi fscalia,
The most realistic CATs available are the 6 from GMAC (the 2 free CATs, the 2 that come with Exam Pack 1 and the other 2 that come with Exam Pack 2). Beyond those, there are other 'blocks' of 3rd-party CATs that are reasonably accurate (from Kaplan, MGMAT and Veritas). Before you rush in to take a bunch of CATs though, it would help to know how your studies have been going. You've been studying since earlier this summer, so what type of progress have you made so far? How many practice CATs have you taken during that time? And how have you scored on each of them (including the Quant and Verbal Scaled Scores)?
Beyond those details, have your overall plans changed at all?
1) What is your goal score?
2) When are you planning to take the GMAT?
3) When are you planning to apply to Business School?
4) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich