Is it possible to get the full suite of unix options for the command line tools on OS X?

Get homebrew and have it install the core utilities. You can then see if the GNU version of cp supports the flags you desire. Here is a good answer on a partner site and I'll excerpt the exact steps you'll need to have cp be replaced by the GNU version if you wish:

Here's homebrew - http://mxcl.github.com/homebrew/
Here's the long story - https://superuser.com/questions/476575/replace-os-xs-shell-commands-with-the-linux-versions/476594#476594

An example of such an environment is Homebrew which for example has GNU sed among other things. Once you've installed Homebrew, you can type

brew install coreutils

and install the GNU Coreutils. These will provide you with sed, date, printf, wc and many other tools that ship with GNU/Linux, but not OS X. However, so as not to "override" default OS X binaries, they will be prefixed with g by default. So, after installing the Coreutils, if you want to use GNU sed, type

gsed

If this is too much of a hassle to type every time, you can add a "gnubin" directory to your PATH and just call GNU sed with sed. You will need to add the following to your ~/.bash_profile:

PATH="$(brew --prefix coreutils)/libexec/gnubin:$PATH"

The reason is that OSX uses BSD command line tools and the Unix tool tip users are probably using Linux which uses GNU command line tools.

You can install GNU tools on OSX (and BSD on Linux).

The easiest way is to use a package manager like Macports, Homebrew or Fink