I used vectran (or amsteel blue) on my boats instead of the steel part. You'll need some smooth shackles on the furler to tie/splice the loop to and you'll probably want to run some mid-pole bridles from the spin pole out to the hulls to give the pole and soft-loop side to side stability. This is the way the initial Nacra F18 was rigged with it's furler... you don't need that steel fitting.

This also let me set the elevation of the end of the spinnaker pole and then adjust the middle elevation of the pole so it didn't carry so much pre-bend (making it prone to breaking).