I'm planning on building an incredibly fancy end-of-year project for my physics class (and my own enjoyment, of course) - an air cannon with a rangefinder that compensates for distance and wind. I've already got all of the equations down in the form of a program in my TI-84, so that part is done, and it should be trivial to implement that properly. I've already got a basic setup built in GarrysMod, as well, so the proof of concept is done as well. My problems are probably going to be in the physical realm; motors, wiring, money, and etc.
I'll probably end up using two stepper motors to control the yaw and pitch. I've never had any real-world experience with stepper motors; any recommendations for inexpensive, close-to-accurate models?
I have an idea for the rangefinder already; I've seen projects where a laser and a webcam are used, and trigonometry is used to determine the distance. I have an incredibly tiny laptop that can figure that out, but then what would be the easiest way to interface that with an Arduino? USB?
Actually...are there any simple ways to interface a TI-84 with two steppers and receive data from a computer? Using a calculator for control would be vastly simpler for me than using an Arduino...It doesn't need to be particularly speedy, and there will be naught but three inputs and four outputs. Any ideas?
(inputs being wind speed, distance, and pressure. outputs would be pitch, yaw, control for the air compressor, and the trigger)
(first project where I'm contemplating using an Arduino, by the way, if it isn't too obvious already 
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Oh well, running it entirely from a microcontroller would be easier then.