Like your idea of making them to factory specs (blueprint) setting up masters to do it. Then they will have the factory base circles and use the stock length mopar pushrods.
The regrind cams to the 340 4spd specs are going to have smaller base circles and will need the push rod lengths looked into.
For someone who wants a blueprinted 340 4spd cam, your price is not that bad. Was about the same price as the last of the Mopar Performance 340 cams were costing when they used to be available at the end of their production. Now no longer available.