Jay... do you know these guys?
http://www.ocean-rigging.com/aboutus/aboutus.htmlChris is a really great guy, I'm sure he makes it down to Naples and could help you out.
If you need help determining the spinlock model, call their U.S. office, best customer service out there! They are located in Newport, RI
I'd second Mike... but honestly I'd upsize to 7/16" for the entire halyard rather than bulking up. Take a look at the blended polypro/dyneema cores to save some money. Here's what we offer
http://alpha-ropes.com/en/inovacao-cotesi/caso-estudo/111-top-cruiser-max Samson has a similar rope
