Don't get Sta-Set X. I build my halyards using a single braid dyneema core, such as samson amsteel... sheathed in a polyester/dacron cover. They are fun to build and give your boat a custom, high quality look. Also the high tensile strength of dyneema means you can reduce your overall line size, making it more affordable. For instance, you can go one size smaller... to 3/8 from 7/16... meaning the halyard has less friction through the blocks(a big plus if they're routed back to the cockpit)... so you'd use a 3/8 dacron cover over a 1/4 amsteel core. The outer sheath only covers the back half of the halyard... the part that is handled and cleated. The amsteel, which carries all the load) runs full length. At the connection end, I built long, luggage tag eye splices for the headsail halyards. Very easy splice, instructions on samson site, minimal tools needed. Most recently I built a mainsail halyard, no eye splice, I use a "halyard knot" tied directly to head piece cringle. I'll give it a chance, but may eventually change to a shackle.... still use the knot over the eye splice though.
Any hoo, Andy, I'm just rambling on because I've got so much pleasure over the years doing this. One more thing, I think you'll find it actually cheaper than buying a ready made halyard of the same quality.
Bottom line......... anything but Sta-Set X. Take a look at MDX if you desire a "club" level replacement. Good Luck.