That seems like a reasonable way to do it, if the robot has to turn an unknown number of times all the way around. For something like an elbow or wrist I would just use some wires with a protective sleeve. As for weather this is a good brand, that mainly depends on if its affordably availible where you live. Also while contact slip rings are by far the most common, they do have a little trouble if you try to send high frequency signals through them, though how severe this is I coulden't tell you.