I would say you could probably find another HEI dist. at the u pull it, but i suppose you wouldn't know if it worked or not either. But you could swap parts out to see, coil would most likely be good, could swap modules, doesn't sound like the pickup is bad since you are getting some spark.
Since it just happened all at once, it seems odd that it could be a wiring problem, but I guess you can't rule that out either.
I'd let you borrow one of my HEI's if you were close to Evansville IN!
I did have a coil that gave out on me all at once, but the spark plugs didn't show any spark either.
Hmmm. Maybe try the module first like you said. Can't be too much money you wouldn't think. Could even get the MSD version if you wanted to spend more and improve on the HEI.