Walmart sells 6-gallon heavy duty storage bottles in the Camping Department - $7 I think. Ours have been filled & in the garage since at the latest October 2001 with no leaks. We should cycle the water out at some time, though.
Food is in 5-gallon new paint buckets. Lowe's does not sell lids - Home Depot does. Home Depot also has orange ones rather than just white, so I bought one of those for a sanitation bucket.
We have 25 - 55 gallon food grade containers that had dr pepper syrup in them for storing water. I bought them for $10 buck a piece from the company that bottles the stuff here. They have been cleaned inside & out with bleach water and allowed to air dry. You need to use a white hose purchased from an RV supply place and a syphon pump to get the water out.
You also need a 72-hour pack for each person & animal containing water & food a flashlight with batteries & clothing for warmth in your pantry and ready to go in case you need to get out quickly.
Every bakery gets fillings and toppings in 5 gal. pails. Should be able to get all you could ever want for half a buck or a dollar each. Clean them out with hot water and they're ready for use.