C-Max is one of my faves, and you can master the step choreography very easily. Let's put it this way - if I can master it, anyone can!
You will indeed need a step for it; you should be aware that the second kickbox segment is step-kickbox, as well as the traditional step segments. A longer step with multiple risers is a great investment for any workout program, because you can use it not only for step and step-kickbox cardio routines, but also for your strength training. I have two, a *blush* Buns Of Steel shorter step for cardio, and the longer original studio step. I place the Buns step on top of the original studio step for step-up drills, and the original step as an ersatz weight bench. (And btw, a step is much cheaper than a traditional weight bench.)
Hope this helps! And consider this your justification not only for C-Max / Cardio Kicks dvd but also the step!
A-jock