I would refer to the wiki for the distro your running myself on which driver to use or google for the list of printers either of the drivers will run.
Either driver will work for the Brother printer, depending on the model.
I just did a quick google for cups as that's what I'm familiar with and use.
Here's list of the Brother printers that cups drivers will run:
http://www.cups.org/ppd.php?L+I20+T+Q
edit: just did another google on lpr and evidently it's intended specifically for the Brother printer:
http://solutions.brother.com/linux/s...r_drivers.html