My prefered way to workout when doing cardio and weights is to start with a 10-12 minute cardio warm-up, do weights, then do cardio. But I want to emphasize strength and muscle tone, so that's why I prioritize it (but I like to have a good warm-up before working out).
Another option would be to split these into two workouts, to allow a bit of recovery time, but not enough so you metabolism goes down much. I've done this with P90 Masters workouts, doing a weight workouts, then taking an hour break, during which time I refuel with a carb/protein smoothie, then coming back to do an Interval workout.