Hi...
As far as the sky...
I have messed with that a lot and the best one I found is by Loopix...
Go to this web site:
http://www.loopix-project.com/Then click on the "Easy" button on the left...
Then click on the "Templates" button on top...
Then download the flavor of your choice...
I recommend the Lite-C version...
It comes with a great tutoial...
And... the models and everything is free to use in your projects...
Their sky system is the best and esiest that I ever found...
You can learn a lot from their code too...
It's nicely written...
Check it out...
Best of luck...