countdown interval timer for exercise class

I am looking for an customised interval countdown timer that can be played on a pc/laptop during a new exercise class that will provide cues for the instructor and participants to: 1. change exercise 2. take a rest/water break 3. stretch for those who have seem the "insanity" workout dvds, we are looking for something very similar to their on screen countdown. The timer can be in cd, dvd or software form but MUST include: 1. a timer bar (countdown bar) 2. the exercise name above or below the countdown bar 3. a 10 second warning before the next exercise begins (preferably denoted by a simple change in the timer bar colour) The timer must also be able to be displayed full screen for visabilty. The full exercise list including times for each exercise, stretch and water breaks will be provided to the winning freelancer. the exercise class will be approx 30 minutes in duration.