Not Cathe here but you can try:
Low Impact Step + Total Body Sculpting
Total Body Stretching
Stretch Max
Basic Step + Body Fusion
High Step Circuit
Core Max
all these are beginner to intermediate.
After those maybe Cardio and Weights, or CTX.
I liked IMAX 2 but without doing the blasts and don't even try to match Cathe's intensity-just "walk through-take out the arm movements to lower the intensity" to learn the footwork because a lot of these steps are used in other step workouts like rhythmic step, step blast, etc.
Tami