How about something that would suit both of you:
A DVD with a warm-up, cool-down/stretch, and 3-4 20-minute segments that can be mixed and matched (kickboxing, step, hi-lo, kb/step or hi-lo with a med ball), maybe putting the 'workout blender' option on it, so you can do the 20-minute segments in any order, and have a new workout every time, that suits your time constraints (35, 55, 75 or 95 minutes, if there is a 7 1/2 minute warm-up and a 7 1/2 minute cooldown/stretch)