it's been a few years since i fished for bill fish, but we used 100# mason and 80# Orvis flourocarbon. The Mason is no fun (stiff!).
I just checked out Trey Comb's book which has the leader set up that I used: 24" 50-60# butt with a loop on each end. 15-18" class tippet with a bimini @ each end. the class is conected to the but loop to loop and the shock is connected with a huffnagle.
I am sure that there are other, perhapse better, ways to do it. Josko?
One cast can change your day...maybe your life.