Matt,
this is a peripherals question more than an iMac question, but I'm going to answer it before I move it.
I have the Brother MFC-8300 which is based on something similar to the 1440, only mine pretends to be a fax/phone/copier as well.
In MacOS 9, it's lousy. It may work, it may not. Mostly, with a few restarts and praying to the right gods, it works.
In OS X, it worked always, once Brother released their 10.1 driver. Ironically, when printing from a Classic application, it never fails to work.
If you have Final Draft 6 and use that and AppleWorks a lot, I would say, move to OS X, where both those software applications have OS X native versions. Otherwise, I don't know what you'll need to do to make it work in 9, but you aren't alone.
Oh, and I'm moving it to peripherals, where printer questions go: