I was looking for some cheap HDRI skies on CGTrader and I saw this for $2. It is a starry sky that looks great to me.
I used a gradient texture for the stars. I used the universal sky from iClone and replaced it with a blue gradient that I darkened.
I also used a glow map for the stars. Youtube video link and CGTrader link. Full Customizable Night Sky 3D model | CGTrader
I used CC3 and brought it in as an accessory and sent selected content to iClone. I detached accessory sky from avatar to make a prop.
I just thought I would share this. It is only $2 and is well worth the price.