there are two types of sigma arms, one is longer than the other, you are better off using rona arms and getting higher offset wheels, control arms that are two long can change the ratio of the action and the moment on the bushes, making suspension adjustment tedious and hard and make the car sort of hobble under load. Ideally you want a short control arm, but more track and a small amount of camber. Track can be had from offset, camber can be had from camber tops, camber is useless without a nice amount of castor.
