If you can achieve .2G, I think you'd be doing very well.
Calculating stepper motors for a target acceleration is very tricky.

Most inexpensive controls use a linear acceleration, meaning you need the same amount of force from start until you're up to speed.
The problem with that, is that steppers lose torque as rpm's increase.
So you have to base your acceleration on the amount of torque your motor will have at your target speed. This may be only 1/4 of the motors rated torque.