for jib sheets
is 1.5x the loa
. That would be 30' on your boat. As for thickness I would go with 5/16 or 3/8 not b/c of strength but because of comfort on your hands. halyards are specific to each boat. get some cheap
cordage and run it up the halyard and place it where it needs to be. Taht is the easiest way. Make sure there is enough tail on the jib halyard to bring the halyard to the bow of the boat. On the main Halyard make sure you can clip the halyard to the rail of the boat. For main sheet you need to know how much purchase
and where you sheet from mid boom or end of boom. For all of these on a boat of your size I would think that cheap
cordage and mearsurements would be the easiest thing to do.
Between us there was, as I have already said somewhere, the bond of the sea. Besides holding our hearts together through long periods of separation, it had the effect of making us tolerant of each other's yarns -- and even convictions. Heart of Darkness