A source for the deli style containers is your local automotive body shop. The shops use them for mixing paint, primer, and clear coat. When the body shops order paint, the paint shops send a box with extra stirring sticks, filters and containers. Usually it is much more than the shop will use on the job. Normally, you will see the mechanics storing nuts, bolts, small parts, etc. in them or drinking their soda out from them.
I received a tree growing in a clear container. One issue I have is the algae growth due to the root zone being exposed to light. The drainage from the bottom runs green. One can get the clear (unused) container for housing the tree and an opaque (used) one as a sleeve to block the light from the root zone.