Impossible to say really as there are so many unknowns with both men. I will say Wills because he beat better opposition but it is basicaly a guess.
Who do you feel were Will's best wins? Some would say Langford who was going blind among other things when he really started losing their series... Didn't Langford score the only knockouts there regardless of that?
Considering there's no film on Wills in his prime, i'm going with the much, much more proven man..... The Black Panther.