Are shoulder fillers and trapezius Botox effective for defining the lines?

I'm really worried about my shoulder line ahead of an important photoshoot, so I'm considering a combination of shoulder fillers and trapezius Botox. My trapezius muscles are so prominent that they make my neck look short and ruin the fit of my clothes, which is really stressful. I've heard that filling in the lines with fillers, rather than just reducing the muscle, really gives that "right-angled shoulder" look. I'm also curious if getting trapezius Botox caused any discomfort in daily life because the shoulders felt weak. I'm compiling a list of famous clinics, but finding one that does a good job with the design is the hardest part. For those of you who have had both done, please share your satisfaction levels and how long the results last.