When I wrote the aforementioned article, I was only doing this on a Linux server. Since then I have become an avid Mac user, as well as continuing my love and infatuation with Linux. On Mac, you have a plenty of the Linux utilities you are used to, but some take some searching, and even then they may not exist or be ported.
In my quest to find an easy way on Mac OSx to combine PDF files, I did run across one. It is called, believe it or not, "Combine PDFs". I know, simple name, but believe me when I say that this GUI tool is pretty awesome! You simply select the files you want to combine and it then not only shows you the order it is putting the in, but it also allows you to preview each page.
The tool is installed using brew on Mac. If you don't have brew, you'll have to either install it. If you don't use brew, you can always try to find it for download. But, I recommend using brew as its pretty handy for obtaining and installing software packages you need and that aren't available through the app store.
If you do use brew, you can install it with the following command:
brew install Caskroom/cask/combine-pdfsAfter that finishes, you will see it in your applications list, as it is a GUI based application.