Weight of 3D printed parts has been on my mind lately, so I've been looking into light-weight PLA/ASA filaments. They're foaming filaments, and I've never tried printing with something like that before, but super heavy pieces like the chest, and shoulders will probably benefit from the weight reduction. Got a video on them here: Light Weight ASA.
I'm rooting for ya! The shoulder attachment seems tricky. I want you to get it all figured out before I get to that part of my suit 