Kriss, assuming it is casting braid you are referring to (?), I think you need to consider more than the breaking strength versus diameter.
A number of braids on the thinner side have questionable shock absorbsing characteristics and have a tendency to "explode" when loaded up and cast with a heavy lure. I don't want to bag any specific product but the ones in question are quite well known for this.
Taking that into account, I would recommend Varivas Avani BigOne (designed as a jigging braid) as the best narrow diameter versus bs braid I have cast in the weight class you mention:
PE3 - 48 lbs
PE4 - 64 lbs
Unlike some of the "super braids" around, never had any problems with this one at all. Expensive for sure, but very reliable in my experience.