By far the preferred way to install TeX Live on a Mac is to use the MacTeX distribution. This installs everything you would need, and access to the TeX Live package manager (either through the command line or a very nice GUI TeXLive Utility) to keep everything updated. Although the initial install is huge, it will cause you far fewer problems in the long run.
If you truly need a small installation, MacTeX also provides the BasicTeX package, which is only 69 MB. Once you've installed that you can use either
tlmgr or TeXLive Utility to install added functionality.
Either of these routes is to be preferred over MacPorts, IMO, because MacTeX is always up-to-date with respect to TeXLive (because it is a TeXLive distribtion), and can be kept updated throughout the year with the package manager. Additionally, most Mac users will assume that's how your system is set up, so getting help will be easier.