First of all practice longtones and try to sound like Lester Young. Sound ALWAYS has more to do with embouchure and air than gear if you are talking about tone. That said I'd say a round chamber a low baffled piece would be a good start. I belive he played an Otto Link mouthpiece I know he played a Conn 10m. If by sound like you mean more than tone. Transcribe some solos and look at how the notes he plays relate to the chord structure.