use 316 1x19 bare wire, with turnbuckles (better/ more frequent adjustment) or multi-purchase lashings of high modulus small diameter line (less fittings, less money), the Suncor kits are good. The high tech lines will save you money for fittings, but won't last as long. Coated wire is now illegal for off-shore racing.

Good article p. 50 Nov/Dec Good Old Boat mag about replacing your lifelines.

cheers, John