If I were you, (wanting wider tires) I'd leave the front tire alone and replace the back tire with something like a 35 or 38. That's where most of your weight is. No recommendations as I don't run anything in that size, just go to your local shop and see what they have. Just make sure you get a tire with a slick tread, not one of those stupid "hybrid" tread tires meant for offroad and onroad. They work poorly in both situations.