IMO would be worth copying the newer Nacra dimensions, The rudder shockcord will only be about 6ft all up and will be closer to 10mm as it has a lot of tension, definitely best to get it from a Nacra supplier because I haven't found another shockcord that holds the tension properly. Best to get some of their stainless clips to hold the shockcord. Definitely worth getting it done by your local Nacra dealer if you can but if not you will be surprised at how tight you need it. Trapeze normally goes from one side to the other approx 1ft longer than your beam length. Rudder pull down on the 5.8's is one piece that goes from one rudder to the other that way you can pull the rudders down from anywhere on the boat and the tails don't drag in the water. Dagger board shock cord is same thickness as the rudder pull up cord, rubs on the back of the boards so needs a bit of size about it. Putting the rudder shockcord on is tricky the first time if your not sure I can explain it but you need it really tight, if you order it from a Nacra dealer they can cut it to the correct length which will save you a lot of mucking around.