I think if I wanted something like that I would speak to a custom leather worker who could make it for me. They could make something that will cover both shoulders, the back of your neck, and strap on in a way that will keep it steady without choking you. I do a lot of sewing myself, but think this would be something better tackled in a more sturdy medium.
Not sure how old your kitten is, but Taco showed a great tendency toward being a shoulder cat when he came home at 4 weeks. He would never hesitate to climb me to get up. I was thrilled, my grammy had a shoulder cat when she was a girl. But Taco pretty quickly outgrew the tendency, so I'd wait to invest money until you know if he's going to stick with it or not. I also found that he had no issues with clinging on with trimmed nails, and as long as they were lightly trimmed he never left more than a few barely pinkish scratches that didn't hurt at all. (which is saying something because my medical condition causes me to feel pain out of all proportion to an injury so any pain whatsoever is pretty much crippling)
Taco and ChaChi