Another vote for the Pertronix. I'm using two of them. No problems in five years of use. One is running with a ballast resistor and one without. I bought mine from an outfit called Retro Rockets or something like that. They each cost less than $70. Do a google search for Pertronix and they should come up.
Speaking of ballast resistors, are you running one on your truck now? If not, it might be part of the cause of your troubles. The cold running problem is probably the Rochester B carb though. I have the same problems with them. I drilled my main jet out a little and it helped. I think the ethanol in the gas these days requires the carbs to run a little richer than they did with 100% gas. The ethanol only has 50% of the energy in it that gas does for a given volume.
