Almond or rice milk can be a good substitute for cows milk
As for cereals, some of them aren't that bad as they're fortified with vitamins and high in fibre e.g. bran. The healthiest option is probably porridge oats though as they don't have any added sugar.
Sometimes making meals from scratch can be really quick and easy and better than ready meals, even if they are organic. After all, you can control what you put in your meal when you're making it yourself and adapt it if you're planning on an exclusion diet.