Okay, I'm trying out the Boss Factory now, and some things I've noted immediately:
There's no male/female division in customization. Instead, there are three sliders for sexual characteristics:
Hip, waist, shoulder and ass with are all on one slider called "Figure". 100 reduces shoulder broadness and waist width, while increasing hip and ass width, while 0 increases shoulder broadnessand waist width, while decreasing hip and ass width.
So if you want your dude to have an ass, you have to sacrifice some shoulder broadness.
And then chest size and groin size are on seperate sliders.
And of course, this is all affected by "Build", which is a traditional Skinny-Muscular-Fat triangle.
Prosthetics are also on the body tab! Three basic styles for both hands and feet, though there's at least two "designs" for each style, affecting what parts are customisable.
And then there's the Modesty options. You can force underwear, or use a selection of censors, where you can choose to use different censors for your nipples and your crotch.
Speaking of, nipple censorship is optional and there are a small selection of sizes if you decide against it. Including "none"!