The easiest would be a set, where everything is rolled up and fastened to the Top. Like what was linked here, Then having a chain drive system to -unroll- things.
I'm guessing the trickiest part of the rig, would be setting it up in a way to have 1 motor unroll/roll different things, maybe a gear set of sorts ?
Lifting up a roll of muslin, or paper for that matter, would be heavy and hard to rig up. As for rolling/unrolling simply Switching the plastic chain that comes with background holders, and putting a bicycle gear on it would allow you to easily hook it to all sorts of motors.
Keep in mind, what was linked can be used for muslims as well, you will need a core of some sort to hold the muslims, but they aren't terribly difficult to find. Some people use spend paper cores from their paper bgs, then just tape the muslim to that.