Try making yogurt cheese, it's not quite a sour. Take a colander, and line it with coffee filters or paper towels. Spoon yogurt into it a put over a bowl, let it "drip" for a few hours. All of the liquid drips out of it into the bowl below leaving a nice creamy yogurt. Add sweetner to that and it is a little like whipped cream. I actually think it might even have a few less carbs this way.