Hi Beth,
Assuming you are like most of us, and will want to "try out" your videos asap, you could start with a rotation of both PS series and PowerHour, that way you'd be hitting each body part 2x/week. I don't know what you do for cardio, so you'd have to incorporate it wherever convenient for you, but you could do something like;
4-8 weeks:
day 1: cardio + PS-Chest/Shoulders/Triceps
day 2: PS-Strong Legs & Abs
day 3: cardio
day 4: PS-Back/Biceps/Abs
day 5: cardio
day 6: PowerHour
day 7: REST
* I don't know how much or what type of cardio you like to do, but you could plug the cardio in wherever it suits you.
That would allow you to both work each body part 2x/week, and utilize 2 of your new workouts. You could then do a 3-4 week rotation of S&H after 4-8 weeks of PS and PowerHour. I don't know how long a rotation you like to do, I usually do 6 weeks, then switch weight workouts, but many here do much longer rotations of 8-12 weeks before changing. It's really up to you and what your body needs and responds to. Through keeping a workout log, I've learned that once I hit 6 weeks, my body stops responding to that particular workout and I have to change up in order to continue to lose pounds/inches. But rotations are an individual thing, you can do whatever as long as you're getting positive results from it, and once the results stop, you know it's time for a change.
Hope I helped,
Donna