Approximate weight of 2 zucchini? Not all are equal in size.

This sort of recipe is pretty forgiving of specific amounts- and it won't hurt to have a bit more or less. I personally don't care to use a zucchini for this that is more than 6-7 inches long, or 2 inches in diameter- so 2 of those works out pretty well. Bigger ones have bigger seeds and are more watery as well- and that's the real threat in this situation. As far as a weight, I'd say you should aim for around 500 grams, or roughly a pound, at least.