vectran is.... not something i would recommend. If you want cordage that is low stretch, doesn't like curves, sun, abrasion, or salt - why not just go for broke and get a PBO cored line?
always seemed like a really kinky line for me. I don't know about II, but 1 could get a mf'er. had it for kite sheets and a main halyard (2:1, 1/4") and it was about as evil as any line i've ever dealt with...
Anything with a dynema core should be good enough for your purposes. NER EnduraBraid should be sufficient for you. Good relatively hard wearing cover that isn't too stiff to cause assholes, good core. Their "euro" braid cover is a little prettier but feels ostensibly the same as the flecked cover.