Don't purchase anything. It feels like you're throwing modules into a rack and hoping that something useful takes shape.

The Mutable Instruments Clouds module is no longer available. However, you can purchase it used or better yet buy a 3rd party micro version. Look for a Michigan Synthworks uBurst or the like.

My advice would be to download VCV Rack. It's free. It also has a virtual version of Clouds. Look for some ambient tutorials on Youtube and start practicing. Once you've learned HOW to make random ambient textures in VCV then start looking at putting together a system.