Topping lift

[Brion Toss]

Hi,
By all means, get rid of that wire pendant, which is too heavy, easily kinked, and inclined to chafe your sail. Endura, covered or not, would be a great choice; covered will last longer. As for size, A 1/8" core will have about the same breaking strength as a wire of the same diameter, and should be plenty for your boat. That's assuming a proper splice.
Fair leads,
Brion Toss