http://www.deutscheoptik.com/catalog/product_info.php?products_id=1718
good cans are hard to find nowadays with the california carb compliant crap. These are expensive but are brand new imports and won't leak. They are made by:
http://www.wavianassociates.com/
I buy the plastic ones and basically view them as a consumable. The 5 gallon ones are generally around 10.00 and last me a couple of years. Actually the spouts seem to go out more than anything else depneding on how and where you store them.
Every couple of years I buy new ones. I like the low-weight and flexibility of the plastic ones versus the high-weight, cost, and "metal-banging" of the metal ones.