Very nice Christie. I can't wait to see it planted.
It seems to me that the hanging ball in question was two hanging baskets that were lined with coir?
https://www.houzz.com/product/...
Then attach the two half rounds together with wire, or? Making a ball.
Fill from the top with potting soil and attach a chain for hanging. Water thoroughly before planting, by setting it in a large container full of water.
You are now ready to plant.
I would anchor the coir to the basket side to keep it in place.