Larry,
I think I purchased a mold for 2oz. - 2 1/2 oz - 3 oz Smilin' Bill style jig heads from Terminal Tackle in NY. If its the right place, they had a fairly significant selection. Midland Tackle, also from NY I think, also had some jig molds.
I also bought a mold which has a selection of ball head jigs for freshwater from a company which was called Texas Tackle or something like that.
A single session, outdoors preferably, will produce enough heads to last a lifetime.
The ball styles seem to work best for heavy tackle, deep, fast water. They give better and easier penetration.
the flat styles seem best for light tackle, shallow, calm water.