I don't know if the person who spoke of a source in PA was talking about Treform spreaders- which are pretty good, except when you have a really stiff branch, in which case you may prefer nails in wood.
The source I use for the Treform spreaders is Growers Equipment Center 800 454-8943. They're in Biglerville PA. They have the galvanized steel Treform types and some others I think. Unfortunately they don't carry the galvanized nails in wood type that work best on thick, stiff branches. The only sources for those pre-made that I know of are in Washington State. Shipping just kills the price. You can double up the Treforms to make a stronger spreader, however.