a fair word of warning...body roll is really only proportional to ride height if you're increasing the spring rates at the same time. You could cut your springs *shudder* and lower the car, however your body roll would be reduced by such a small margin that it would be completely outweighed by the fact that you'll be crushing your bump stops and killing your shocks...not to mention your performance might actually be worse. My point here is that you'd need to get a set of aftermarket springs or coilovers to really make a difference, as TheOtherDave™ said.

If you're on a budget, go with a new set of springs and shocks, but if you're gonna do one, then save up for the other, get the shocks first, then the springs, because if you get springs alone that drop the car more than like .5", your shocks are gonna crap themselves in a couple of months...unless you'd be getting the two within a month or maybe two of each other.