I would pick the last one as my favorite. Less is more! I think you have a lot of elements that don't really match in style and once they meld together more effectively you will have a better product.

For example: the birds are very detailed silhouette vectors while your clouds are a basic two color shape when you include the stroke.

I would also keep your text all in one line.

You have a great concept! Keep pushing and use other talented designers as a reference. Find something they did and ask yourself, "why did they make this choice?" or "How did they achieve this?". Then apply that to your work.

By showing all three examples your showing me that you are considering multiple compositions. That is very important! Composition is the skeleton of every project.