I want really exceptional strength in all of my pulling techniques, as this helps with my submissions and pulling in general for jiujitsu.

I want to know what you guys think is the best Bicep excercise that would translate into more pulling power? I'm thinking Hammer Curls? How about Drag Curls?

Also for pullups, you guys think the underhand grip would be best for maximum pulling power? I will switch up grips regardless, to ensure strength in different angles.

Thanks in advance fellas!