PowerPoint Presentation

I own a gym. We have large classes lead by an instructor. The classes have exercises that the students perform for for various intervals. Usually 3 minutes at a time with 30 seconds to a minute of rest. The classes last 30 minutes each.

I want to create powerpoint presentations that last 30 minutes and play automatically once the "enter" button is pushed on a keyboard. The presentation would start with a frame that shows the entire workout summary to follow. Then, each exercises written description would be displayed for the time that it was to be performed. For example, after the presentation is started, the first exercise might be "jumping Jacks", so the screen would display the words "Jumping Jacks" for the allotted time the exercise would be performed (usually 3 minutes). In addition, I want a count down timer to be displayed that shows the time remaining. After the time allotted for the exercise is completed, another exercise name would be displayed (or a timed rest period) and then, the next exercise would display for, say, 3 minutes and so on for 30 minutes.

Currently, we write these workouts down on a large dry erase board and the timer for each exercise is controlled by the instructor using the iPhone stopwatch app. My desire is to project these workouts onto a television in order to have a more polished presentation to our customers.

The presentation would need to be attractive and changeable. I want to be able to create multiple workouts using the one you produce. I would change the exercise names displayed and then save each modified workout as a new workout. I want to be about to have presentation "modules" in the following increments: 30 Seconds, 1 minute, 1.5 minutes, 2 minutes, 3 minutes.

I hope this is clear!! I can help with details to clarify to the prospective peroson who does this job