holy thread hijack.
Mike_arnold. If you go with a bigger wheel you should proportionally go with a tire that allows the rotating diameter to be the same as the stock wheel and tire.
Everyone is saying upgrade your suspension, if you were to put bigger diameter tires/wheels on it then yes MAYBE get suspension if you would like as they will limit the suspension travel. If you keep the tires/wheels diameter together the same then you won't need to worry about it. But try to keep as close to stock as possible.
And about body roll, if you get excessive body roll it may be shown more prominently by softer struts. However, If you were to change your Caster and Sway Bar you would effectively combat the motion from the start not relying on your struts to combat the forces.