Yelsanick0117 might be able to help you, or you can use his instagram posts for reference. (nick_yelsa117).
he also suggested to me to use yana hana hex black fabric, it is sold at joaans and other online resellers.
For his plan, he used a morph suit, made a muscle suit out of upholstery foam and glued/stuck it to the morph suit. then sewed the hex fabric on top of it. However He suggested not to do this as it can get very warm. so try making the muscle suit one suit if you can help it.