Where do you get zebra printer fonts for print preview?
After much research, I discovered that the fonts Zebra uses are tightly protected because of licensing.
Contacting Zebra about obtaining a license for the fonts is your only option.
The alternative I'm using for now is to preview the label with a free-to-distribute monospaced true-type font (which I haven't yet selected). The document I linked in my question provides size and spacing information for the built-in fonts so I can emulate as close as possible.