But I'd like to get that MONOPHONIC playing he improvise, with a tone that is not heavy, not a lot of distortion
um, he's using a LOT of distortion/fuzz in the video.
Neck humbucker, tone rolled down, complete control over the attack and all the strings at all times.
Muff like distortion/fuzz boxes do this very well, just keep the 'Tone' control low.