Bigdog said it best. Pounds, ounces, etc don't really matter that much since the servings will not be weighed out. The serving is controlled by the size of the utensil used to serve the food. It is the serving size, in volume, that will matter. We use a standard 4 oz serving spoon for sides and tongs for meats. If it is self serve be aware that the guests may take more or less than 4oz with the tongs.
It also depends on the depth of the Full or 1/2 pan being used. The following should give you a good idea of how much your pans should hold.
A 2 1/2" deep half pan holds 4 quarts. That's 30 half-cup (4oz) servings if you figure you really can't fill it to the top, but who will eat only a half a cup of anything, adjust according to what you're serving. The 4" deep half pan holds 7 quarts, or about 55 half cup (4oz) servings.
Do I smell SMOKE?????