I used a nude baby figure for my Madonna of the Polygons piece, and I ran into the same problem. It's going to step on your plans, but I really doubt you'll be able to find it and the Mike gens won't translate well.  I recommend strategic posing, like I did, and perhaps throwing a drop cloth over the figure's loin area so that it isn't so obvious that you're going without.

Seriously, it doesn't matter how artful your intent is, people get very squeamish about kid-bits when they don't know you personally.  I got the gasps and lynching vibe when I asked around, and I'm a mom; I cleaned kid bits for years.  Even if you do manage to render it, your reception will suffer for the inclusion, the concern being that while you may not be a pedo, authentic pedos can use your picture For Evil.

Good luck.