Suggestions/Tips for Running Addressable LEDs with Pi 3

I have a small project that I am working on involving the simulation of the sun's transit across the sky and occlusion of sunlight by passing clouds. This would be achieved by having two separate strips of addressable LEDs powered/controlled by a Pi3 that is networked via WiFi to a central computer. My questions are:

  1. Do I need an additional LED controller of some sort on top of the Pi 3 to run two ~7ft 5v strips of white 8000K+ addressable LED's or does the Pi 3 have everything it needs already?

  2. I know there are a variety of distros to choose from but are there any better suited to controlling LED's in particular?

  3. I will need a program to keep a portion of LED's at full brightness while the rest will be dimmer in a gradually decreasing fashion leading away from either side of the "sun". The bright area will then gradually move further down both strips (the strips are parallel to each other spaced apart about 1ft) as the day goes on. In addition, I will need a ripple effect of sorts that can dim even the brighter LED's to simulate passing clouds. Is there a particular place I could look to learn how to program these effects?

I've been trying for weeks now to track all this info down myself but I decided it might not hurt to ask those who have more experience working with the Pi ecosystem. Much thanks in advance!