Bakuretsu Hunters from 1995 ticks pretty much all of those boxes. At least if you include the OVA from 1996, since that went kind of wild with the Ecchi. So you got
the red haired girl with the suspenders, the blue haired girl of whom I can't find pictures without her boobs exposed and it's a show about hunting monsters. Maybe
this scene that this show had instead of a transformation sequence was memorable? (But not sure if it showed up in the OVA.)