Can't help you on the 10 inch wide part, but you can get 4x6x .010 galvanized material at a lumber yard. It is commonly called "tin shingles" a more correct name is step flashing. The last ones I bought were .29 cents each. Some lumber yards sell flashing in various width up to 24 inch, by the foot. It will be thicker than .010. I always make my own tanks. The material cost near nothing, but the labor would be pretty poor pay. The nice thing is you can make them the exact size and configuration that you want. The can idea will also work if you have one,