I cannot speak for the quality of any of these - in fact, they are probably all things you don't want to use.... But:

Keel - http://dimwalker.com/q4models.htm
Idgirl - http://planetquake.gamespy.com/View.php?view=...&id=62
Ryoka - http://planetquake.gamespy.com/View.php?view=...&id=53
Hitomi - http://planetquake.gamespy.com/View.php?view=...&id=54

As a little teaser, here are some that I don't think we're ever publicly released which is a shame as they look good:

Patriot - http://pioroberson.com/modelpages/info_patriot.htm
Aqua boy - http://pioroberson.com/modelpages/info_aquaboy.htm