Here it is! Thanks to all the folks who shared their intellectual labor.
I didn't have the knowledge do put together a stir plate from parts at Radio Shack... but I did have a hobby in a past life that provided the answer: The old model railroad transformer works well as a rheostat.
I also lacked the nice plastic box in pretty colors so I went basic: I just cut out the center of the fan guard (so it wouldn't interfere with the magnets) and that serves as the platform for the beaker
Since I went cheap on everything else, I figured why stop there: I used a wide mouth glass bottle (1 pint / 473 ml) as my beaker. It may not be able to produce a batch as large as the 1000 ml beaker, but it gets the job done. It also accepts the airlock stopper just fine.
So what do you all think?