I got the 18qt square one to use with the Anova 1.
I got two lids which sell separately anyway. One I cut to fit with the device, the other for when I might want to use it for something else.
I used to use a DorkFoods controller hooked to a large rectangular roaster… I used racks in that to both hold food down and space it off the bottom. Things wanted to float in it for some reason.
Currently I haven’t needed racks as the food seems to behave better in the vertical position that is natural in either the pot or the plastic container. I do use a binder clip to clip the top of a bag to the pot sometimes.