This thread would be better suited to the fabric and sewing subforum, fyi.
You've probably seen the thin variety of "regular" raschel-knit spandex and assumed that all spandex-containing knits are like that. As stated, there's a hue variety in fabrics that fall under the "spandex" umbrella (which, really, I wish there was a better term for this type of fabric, since it's so specific to a certain family of fabrics, but so non-specific within that family).
I've found multiple references for this character that can be made of several different fabrics (as in, the material seems to change drastically from reference to reference), but it sounds like what you are looking for is something along the lines of a matte milliskin. This is a bit thicker than "regular" spandex and is not at all shiny. From what I've seen of this character, I don't see a way to even incorporate non-stretch fabrics into the suit, or a way to have a fabric with less stretch and recovery than things under the "spandex" umbrella.
If you find skin-tight knits generally unflattering, then that's a problem of either fit or undergarments. If a bodysuit does not fit well, it will pull and gape in unflattering places, which can be a common problem with off-the-rack zentai suits and the like. Otherwise, if you find that these materials show too much of your body that you don't want shown, you should look into shapewear to put underneath to smooth out anything that would prevent that (mostly unrealistic) 'comic book' look and figure. You wouldn't look for garments that would make you smaller as much as garments that would smooth your lines. Full torso shapers might be best, to prevent any flesh from possibly spilling over the top of something that ends partway on your torso.