Can OS X use apt-get? If there's an apt repository for OS X the main part may be already solved. The second questions is how to create a minimal system, where we can chroot into. Debian is using debootstrap for this, but what is OS X using? For Suse, RH and fedora there's a project called mach (http://thomas.apestaart.org/projects/mach/) which can build a chroot.
If we can not install OS X packages with apt-get, we have to adjust the script install_packages.
The fink project is used in OS X for installing a bunch of ported unix software on OS X. It uses apt-get and dpkg to do this, so this could possibly help solve some things. Getting that minimal system may be difficult though, as the unix backend of OSX is ported from FreeBSD.
http://fink.sourceforge.net/ for more info.
Nicolas.
