If you install the springs and the rear camber comes out at a number you dont like then yes, pick up a set of arms. Install them and then go back for an alignment. Same with the fronts, but at least on the front a set of camber bolts is only $30-ish. Tough to install but cheap. Just depends on what you want. If you are lucky and end up with close to 0 camber in the front and say -2 in the rear, a very aggressive rotation schedule should help you out a lot with wear also. Lemme go take some pics of my worn out summer tires.... they are totally beat and getting replaced very very soon.