I'm running a yellow top and changed the alt to a 140 amp delco. for pretty much the same set up you described.
i don't know if it was the age but my stock atl craped out pretty quickly when i put those light on and winch.
had 3 and all went to pot, never buy own again.
sorry to here but you might want to have your regulater checked if your having that many poblems.
ive had my yellow top in my truck for five yaers now with out an issue. and none of my buddies have had any ether.
Dual optimas, never again. Died a rather sudden death and left the truck stranded. Trying the Diehard Platinums next.