This has been driving me a bit mental for a while now. "BSD != GNU" tools!!!!! I have macports installed, you can enable variants when you install packages. There used to be a variant called +with_default_names, it used to be possible install coreutils and findutils so that they aren't prepended with g. They recently removed this variant and it confused me a bit. It seems that they now have the normal binaries without the g in front of the gnu tools located in /opt/local/libexec/gnubin/.

So all you need to do is just

sudo port install coreutils findutils
export PATH=$PATH:/opt/local/libexec/gnubin

It depends on if you want the extra gnu utils underneath the BSD layer or the GNU layer on top, so experiment with the order of the PATH's