I ordered some parts from Sparkfun which arrived yesterday.
The orange LED buttons I got are too small, and they don’t fit easily on a breadboard because of the arrangement of LED leads. I did get a little breakout board that helps now that a friendly EE soldered it up for me (I really need to get a soldering iron). It’ll at least let me test some things, hopefully.
The rotary encoders I got are “ok” — they may be a bit small, and the “click” when you turn them is pretty weak. They’ll do to start playing with things once I can get them working.
I also got some green EL Wire and the appropriate connectors and inverter for the EL project.