If you’re impatient and want some dense WS2812s right now, I have unpopulated boards that hold 5 LEDs each, and a reel of them. Works pretty well when you reflow them well, but is kind of a pain if you do it really sloppily (like me).
https://drive.google.com/file/d/0B3_kCL0lNAM9RER3OXEwcEk4Yk0/view?usp=sharing
I panelised them, so, uh, I have some extras.