i have a 24v drill/screwdriver but set the torque to the lowest setting. As soon as the steadies touch the ground the drill stops driving. I then give half a turn with the hand brace.Isn't a 18v drill a bit overkill for steadies.
A 12v one would save a bit of weight and reduce the risk of overdoing it. If you lower the steadies too far, you take the weight off the wheels and cause extra stress on the chassis.