I have the LIPAVI 6.5 gallon (26qt) container and lid; there are pictures of it
here. The lid is made to fit the Annova.
I don't think the ping pong balls are necessary when you have the lid.
BTW, I really like the container and lid combo. Easy to use easy to take care of and not to heavy to lift to/from the sink when full.
I also purchased one of the LIPAVI racks -- I got the
round one because I purchased the rack before I purchased the container, and it fit my
stock pot. If I had to do it again, I would probably pick up the rectangular or square one.