Wow, quite a hostile post there Paul.
Not at all! Perhaps you should read
the reference.
The references I cited list all the information I had, so I deemed it unnecessary to repeat all that.
OK, you got me. You said WS2803, which is hens teeth, I was thinking of WS2801 (or WS2811/ WS2812) which are available in droves and well documented in use. So I didn't deem it necessary to chase down your links.
However with some further digging, I did finally find the Neopixel LED from Adafruit and that is exactly what I needed. Just needed someone to point the way. Thanks for your post.
The "NeoPixel" is of course, the WS2812 whose one-wire drive requires special coding - which is of course available as a library. The WS2801 uses a clocked two-wire interface which is much easier to work with.
As to your original point,
Worldsemi is a wholly Chinese company, representing the way China has acquired "Western" technology and made it their own, so you need not
expect their products to necessarily be available anywhere else. The WS2803 has a more niche market than the other chips and is thus not available on eBay, let alone American (or "Western") sellers. Adafruit of course sources its parts directly from China without a local "middleman". Similarly with SparkFun. But the Chinese manufacturers of their projects then offer them direct on eBay. Just as well for those of us outside the US as US postage fees are completely prohibitive.