I'm not trying to say you are wrong, but how do you know they are all busted up? Have you pulled the lower control arm bolts off and actually looked at the bushings? If those two bushings are bad then your steering is effected and your tires will be wearing very poorly, but you have not mentioned either of the two most observable results of bad lower control arm bushings.
Do your tires usually wear out on the inner side yet still have good tread on the outer? If so then get a set of eccentric bolts, install then in place of the original bolts that are installed from the factory. Using the eccentric bolts will change the camber so your tires will wear evenly on the front.
If your back tires are wearing well then leave that alone. If it isn't broke, do not fix it.