Tire size for 72 Duster

I have some Crager S/S rims for my 72 Duster (Rear 14 x 7 and Front 14 x 6) and was wondering what wall height would be good to go with. I also want to give it that aggressive stance with the rear of the car up a bit. Would bigger tires in the rear affect that at all? If so, what size should I go with with or should I just get the same size tires all the way around and only adjust the torsion bars?