I would use the same spring style that was in it. I assume it was coils, so do coils. Adding leaf srping would be a lot harder imo, because you would have to start from scratch.
What side pumpkin is it? Drivers side? If so then ya High pinion out a of a 1979ish bronco would be a good place to start, as they had coils from the factory.
Take some dimensions and http://77cj.littlekeylime.com/Dana44_3.htm
use the weatlh of info Mr. N has to offer.