Where can you find containers appropriate for water storage?
Pop/Soda bottles are readily available (some already filled with water) at grocery stores. Larger storage containers can be found at grocery, home, or super stores. Sometimes camping supply stores carry the smaller containers. Make sure you buy food-grade plastic for water storage. Blue is the universal indicator of water storage. Blue containers also inhibit light within the containers which helps reduce undesirable growth. Opaque is better than translucent, colored is better than clear. I don't promote or vouch for any outside internet sites. But I can point you towards some stores that carry and/or ship their products.
Here are some:
Emergency Essentials - Their products tend to be way overpriced, unless purchased with a group discount or on a great sale.
Walton Feed - Prices are more reasonable, but shipping can be expensive and slow (unless you are shipping with a group via truck). If you are making a trip to Montpelier, Idaho, you might be able to pick items up.
Maceys - Stores in Utah almost always have water storage containers on hand. They have sales once or twice a year.
WalMart - You might find water storage containers at WalMart.
Camping Supply Stores - Generally have the smaller containers.