I see you posted over on the AACA site also. Your answer may come from them as they are more in tune with the neat really old cars.
I see no reason for a ballast resistor. The coils with a higher primary resistance will lower the current drain from your system so I see no harm in that. The spark voltage will also be reduced somewhat. If starting is not a problem then I would just go with the one that most closely matches your old one.
