I am planning on making a basic flood and drain wheelie bin system in my basement with a 2 GB to 1 FT ratio. There are basically 2 sizes of wheelie bin that I could use, two 55 gallon (200L) bins or one 96 gallon (400L). I know that generally speaking, the larger the FT, the more stable the system. But the larger wheelie bin is much taller, and not that much wider, which I know is not ideal either.
Make sure that the bins you decide on purchasing have very stiff sides. Some bins will tend to bow out of the center when filled with water and gravel. Also, when you fit plumbing to the bin, the stiffness will keep your plumbing in place better. Some plastics will tend to crack when exposed to water for long periods of time. I would stick with PET plastics (milk jugs). I have used the blue recycle bins for cans with success, albeit I wish it were stiffer. I actually prefer a fiberglass container, due to its rigidity, and its ease for cutting holes and fitting plumbing.