Small diameter vectran will fit your bill. Most vectran now has a coating for uv resistance but that is not an issue as it will be in the luff of the sail. As for abrasion vectran is strong in this department so no worrys there. I can tell you that pulling with small high tech line is interesting. I work at a car dealership and upon receiving a package from APS containing 5/32's vectran line and commenting on the breaking strength of the line I was told I was full of it. Money was wagered and we picked up the front end of a wrecked pickup truck by looping the line under the truck and then tieing it to the arms of a vehicle lift. The dry weight of a silverado is 4780lbs and we only picked up half the vehicle, but it was the heavy half with the engine.