Unfortunately, we don't sell out CATs as a separate product. You can, however, purchase GMAT On-Demand, which is a package of online resources including quizzes, workshops, 9 CATs, and On-Demand video lessons.
As for you score, congrats! 660 is a great start. Keep working and take pride in your progress, but don't get too hung up on practice test scores. Even the official GMAT-prep scores aren't fully representative, simply because the experience of Test Day is very different from taking a test in your own home.
Prepare with Kaplan and save $150 on a course!