RE: Please help!!
I don't understand why your store doesn't carry frozen yogurt-- I thought most grocery stores did. It should say "yogurt" on the carton. I think that some frozen yogurts say they have live cultures in them-- not sure, and the taste is a little more tangy, IMHO. (I like to serve my home-made Tollhouse Pie with vanilla frozen yogurt because it's a nice contrast to the rich sweetness of the pie.) I can't answer your question of which is less fattening. I would just suggest that you read the labels on both frozen yogurt and ice cream. There are plenty of low-fat and sugar-free frozen desserts out there, but you have to compare calories and amount of fat in each serving. And don't forget to see what size they consider a serving. It's usually 1/2 cup.
Some dieticians say to get a premium ice cream, but just have a few bites, that it's more satisfying than the low-fat or sugar-free ice creams/yogurts. But how many of us can stop after a few bites?