Amsteel and Dynex Dux might be more appropriate for standing rigging; any of the newer low stretch ropes like Sta-Set will do you fine for halyards. I still don't think there's much wrong with good old yachtbraid for whitesail sheets, but I'm sure you can spend more than that if you want to.
Lightweight water resistant sheets for spinnakers make sense....
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"