Stonyfield is great. Lots of cultures. Makes no difference low fat/full fat, except in taste as Ladybelle says.

For Fitday, enter your yogurt as a custom food and just put 4 g per cup.

My protein shake is:

.5 cup yogurt
few frozen berries
4-5 ice cubes
1 scoop vanilla protein powder

(chop the ice and berries in the blender first then add the other stuff)