M_Boats: Halyard line

Hello all, I am looking to replace my old wire-to-rope halyards with all-rope ones. The ones I would be buying would be from New England Ropes, Sta- Set, and I would need some advice on how thick a line I should go with. Would 1/4 be enough, or 5/16, or do I need thicker line? These lines have tensile strengths of 2000lbs (1/4) and 3000lbs (5/16). Does anyone know what the newer boats come with? Also, has anyone measured their masts (I assume I need about twice the length of the mast for the length of the halyard). Thanks, Andrei.