Missouri Bullet Co supplies me with my lead, but if it is too much, maybe a local bullet maker will be able to supply your needs.
Missouri Bullet uses somewhere close to 30 tons of lead a month, so a few extra ingots shipped to them from the mine are going to be cheaper than me ordering from the mine.
I do not use the lead for bullet making (I use it for fishing weights) so I do not know how easy it is to take lead back to the pureness state. The folks in the bullet casting section might know the answer. http://thefiringline.com/forums/forumdisplay.php?f=43