Hi- I just purchased 2 & 4 oz tins from specialtybottle.com out of Seattle. These are food quality, which they don't need to be for a lotion bar, but they have a nice finished look to them and don't tend to corrode as plain tin would. I will be using the 4 oz tins for round soaps and could not put anything corrosive in a regular tin. These are coated and look really nice.
If you want the regular ones, they can be purchased through papermart.com. I found the prices comparable.