I've read the discussion about the X11 mouse theme in the chatroom. To be honest: Why do you want to use a white cursor theme? X11 uses black cursors by default since ages and I think we should go for it.
My suggestion is http://gnome-look.org/content/show.php/ ... tent=73135 which I've used before switching to KDE.
PS: The KDE4 default theme is even better