If you want to weight train, you won't go wrong with the Gym Styles.
For cardio, KM, LM and IMAX3, like you're thinking.
For endurance, MM, HSC and CM.
My favorite workouts are low max,kickmax and high step challenge.Low Max is a great step workout without high impact but intense.Be sure you will work your legs hard. I love kikcboxing. Kickmax is a great kickbox workout. If you don't like high impact you can skip the kickmax challenge and do the leg drills. My other favorite is HSC. The music is great and I love the circuit workouts because I can mix the cardio with the weight training in the same workout. Hope this helps.
If you bought HC Extreme you would end up with most of the cardio from Imax 3 and LM in really fun and tough combinations plus you could program your DVD player to play the Imax 3 Intervals straight through as well as the LM sections to get a feel for the cardio as produced. You would also end up with the Boot Camp Challenge and Leg drills from KM and some from HSA. Then you could get Muscle Max and GS Legs or HSC. Or you could get HC Extreme for the cardio benefits, MM, and then pick a workout from an older series that has two or three workouts on it. Good luck with your decision!
Angela:7
I would get Gym Style Chest and Triceps, Gym Style Back, Shoulders and Biceps and LowMax. I think the Gym Style Upper Body Workouts are the best upper body workouts that Cathe has ever put out and LowMax is the first of its kind and its great cardio.