... it would be nice if you made your videos public.
+1
It's a shame you couldn't get the stepper to work properly - what exactly was wrong? Too big of steps/too much jerkiness? A servo might be nice -and the speed control is darn easy in PBASIC (I played around with a BOE-bot awhile back for a microcontroller class). Just make sure you get continuous rotation! Otherwise you won't be pumping anything. If you're ordering straight from Parallax, however, be advised the internals of servos are built mostly of plastic or nylon and their service life in high load environments is limited. Another way you could try is with a basic DC motor and motor controller. You could use a PWM controller, or you could also change the pulse width and frequency with a FREQOUT command to control speed to some degree.
Your project sounds really cool. If you woudn't mind, could you upload your program or email it to me?
