If you want to use it for shrouds, forestay, and bridle, you are going to have to go with something like PBO and that stuff is not cheap. Another option is rod rigging, I've only seen it once on a beach cat and it was an A-Cat. Absolutely zero stretch I think was the goal. The new high tech lines are adequate for rigging, they just aren't idiot proof the way wire is.
I've kicked around building a set of shrouds. The best way I figured I could minimize the creep was to hang weight on the line, (like 200+lbs), and then twist it up and walk away letting it untwist itself naturally. I think a few times of having weight on it, and being spun around would allow it to find home and take out most of the issues of the line creeping. The forestay I'm a bit leary of.
I use spectra/dyneema where ever I can.
-main halyard is tapered with a dyneema tail so there is nothing but 1/8" line in the mast when the sail is up. Not really neccessary, I'm just a retard.
-spinnaker halyard is basically the same way.
-I spliced a tail in my spin sheets for tying them to the clew
-Spinnaker pole bridles
-Tack line for the spinnaker is dyneema in the pole spliced to a single braid for the cleat and take up system.
-My down haul is a cascading 16:1. 4:1 to 2:1 to 2:1, all but the last 2:1 is dyneema.
-Trapeze lines I put a small bit of cover on the top to protect it from chaffing.
-Trapeze return lines, one end spliced to a dog bone, the other spliced to a sister clip with an aluminum stopper.
-Main sail blocks attach with a loop of dyneema and a stopper ball.
-Spinnaker bail is supported by a piece of dyneema.
There's probably something else too, but I can't think of it.
I just had another thought, I wonder how well it would hold up on a H16 with the floppy loose rigs. That might create some issues as well.