worth look at https://youtu.be/_dH4H57UsJU   standard fibre glass works just fine. there is a ton of marketing BS with insulation.

just be careful where you install products like vinyl. anything that stops moisture can cause problem. i would not recommend Mass Loaded Vinyl on outside walls or a bathroom wall, or on both sides of a wall.

the other thing is air gaps. tiny holes let sounds through extremely well. making sure gib is well sealed to other sheets, sealed to the timber, especially celling and floor. any electrical outlets really need the box sealed.