I found some sources for the small balls that can be used for contact juggling or “finger qigong”. It was just a matter of trying some google searches until I got the right terms.
This search finally got some results. It looks like Acuspheres or Reflex Balls are terms that work. These seem to have chimes in them, so not for practicing late at night if you have roommates or neighbors.
You can also get acrylics of any size from 1/4 inch to 3 inch from Tap Plastics.
I tried Google Products and found some stone spheres. These 2 inch steel spheres look good, too.
If you have any sources that you like, please comment!
