I missed this post or I would have replied sooner.
Yes, that LED grid you linked looks like the right one. It’s a common panel that’s distributed by several people out of China. My PCB mates with this connector, which you would crimp onto the LED panel wires:
You’ll obviously need 3 of the female pins too:
As you said, Adafruit and others have lots of strips of WS8212b LEDs. You just have to use your imagination and decide how big you want the grid (i.e. how much space do you want between the pixels). You can certainly cut a strip into 16 parts, each with 16 LEDs, and then use wires to solder them together in a zig-zag series (starting in the top left).
Unfortunately I do not have plans to release the other designs or schematics. The design is really straight forward, and should be easy to mimic. I’m actually much more interested to see what you guys come up with.
As for the layering, maybe watch that assembly video on Kickstarter. Basically it goes:
black paper grid