Hi Chris, try this:

http://www.3dcontentcentral.com/Search.aspx?arg=Humans&page=1

Use the STEP format download option to get something you can read into MoI.


That's one that Danny suggested from this previous discussion thread, also see his message for a file attachment that contains a figure as well:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3969.14



You might also look at http://grabcad.com for some models there, like:
http://grabcad.com/search?utf8=%E2%9C%93&query=human


- Michael