yes, they will... a good rear bar makes a world of difference on the sol... I wouldn't recommend changing the front. High quality shocks/springs or coilovers(this doesn't include the ebay special stuff that sells for super cheap... it'll cost you a pretty penny) and a good rear sway make a world of difference for reducing body roll.

If you're worried about reducing body roll with a sway, I assume you've already lowered the car with some good suspension components.