The best horn for lead... IMO is the Calicchio. The 1sZ/3rL or the 1s/2 or 1s/7.
Calicchio has about 5 or more different models that are considered to be GREAT lead horns.
Of course this is just my opinion but I think these horns will get the job done over all others for strictly lead playing. Models like the 1s/2 are dream lead horns but are great for Jazz and Commercial playing as well. Ask Freddie Hubbard!! He plays on a Calicchio 3/9 Large Bore. Chuck Findley plays on a 1s/2 and Lee Thornburg of the Tonight Show Band plays on a 3/7. Claudio Roditi plays a 3/9 Ultra. (Heavy model)
I play a Calicchio R32 and I do ALL of my work on it. Right now I cannot even think of playing any other horn so that is why I will put my vote in on Calicchio!