I think you'll find this article by Tom Venuto interesting esp. since you want to gain muscle and lose fat at the same time which is basically what his book, Burn the Fat, Feed the Muscle is about. It is a long article that discusses proteins, and food vs supplements. In general, he writes that:
Aside from convenience, the truth about protein supplements is that they offer few advantages over protein foods. There is no scientific evidence that you can't meet all of your protein needs for muscle growth through food
(as long as you are getting your complete proteins with every meal).
He also has an article about milk (and chocolate milk) as part of your body recomposition program.
Surprisingly to many people, dairy proteins keep coming up winners. In fact, numerous studies have suggested that good old milk is excellent for both post workout protein as well as re-hydration.
It sounds like you are on the right track with your low fat milk.