Hey man, they look great! I think the choice of chain or rope is very personal. Personally I prefer the rope, the possibility of wheel spin and finger better than running, but double, I think the chain is the best visual effect.
I'm not one of these, then not tell you how much last. But I believe that should last long enough. You can not see very well, but in my photo are aluminum nunchaku with rope, I bought from a guy who made himself at home, since they have more than one year, they fall straight down, and still not break nunchakus . This is done by a company I think is very durable.
The only drawback perhaps is that they are hollow and lightweight, if you take a big hit among the two, you can knead them. The mine has crushed several brands, which have generally been when I was coaching cross-over (two nunchaku rotate inside the other).
I think it's a good choice of buy. Independent of whether single or double.
Good luck with your choice =)
