LR Plastic Water Containers

[ensquire]

I would like to know where the best place to find water storage tanks.
I would like 2 barrels or containers in the 55 gallon range for a water storage and mixing station.
New or used, if someone has such things and is looking to rid themselves of it.

Also looking for a water container for my ATO, the space I have available is 9 1/2" W x 15 3/4" D x 20" H.
Any ideas or suggestions here are most welcome. As of right now I am considering a glass tank built locally. But i'm guessing that there are much cheaper alternatives.