Loads of them in the Marketplace here and on Daz. Try ShareCG for free ones, I don't know if there are any, though.

BE AWARE that not all M4 skins include a map for the genitals, check the readme for whatever product you're looking at, if you need that bit! 

FREEBIES! | My Gallery | My Store | My FB | Tumblr |
You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.