Buy the Hobie chute for the 18/18SX - it seems to work well on the boat. I used a 12.5' pole length which gave a good slot between chute and main without excessive lee helm. Don't go for the 8.5 ' pole length hobie recommends on their setup instructions - the slot is way too small.

Locate the spin tang no more than 1/3 the way up the comptip (to keep the stress on this rather delicate component manageable) and the adjust your pole shrouds to vary the height of the tip of the pole to get the right luff tension. I used vectran for the shrouds which is easy to adjust and seems to last well.

With this pole length and chute you won't want your spin sheet blocks on the rear cross bar - it would pull the foot too tight and open the leach too much. You can get the clew re-cut to let you fit blocks off the side shrouds, or do what I did: mount eye straps through the outside deck lip some distance behind the shroud and spread the load under the lip with some stainless bar stock that the eye strap bolts through. This has lasted well with no cracking. I mounted a second pair of turning blocks on the front cross bar, one in line with each hiking strap, then a pulley on a bungey that sucks the slack towards the back cross bar. I had a doubler rigged and ran my hooks off the rear cross bar which was a bit of a compromise on sheet angle. If I did it again I would rig the hook off the spin sheet block's eyestrap on a short length of line and have some small shock cord from the hook to the shroud to hold it out the way when not in use.

Chris.