I used to fly TD .049 foamies that weighed 5 or 6 ozs at about 120 square inches for combat. These planes were required to fly with .012" x 35 foot lines. They could stall in over head flight if you weren't getting a perfect screaming run.
.008" lines would have helped for sport flying, but they aren't cheap and 1 little kink ruins them. Spiderline fishing tackle works and is 10 times more durable for flying lines. 30 pound works great for .15 powered planes, I'm not sure I remember what weight you could get away with for 1/2A, but I'll bet something like 15 pound is what works. I do remember trying it out with a Cyclon and having no problems. The ends of the lines are simply wrapped around brass eyelets a few times and tied off, no crimp sleeves needed.