The offset on the original rim is +18mm so anything below that will stand out more than the original rim and give you a more aggressive stance. Also the standard width of original rims is 8.5 inches, so a 9 or 10 inch width will also give you the more aggressive stance. Only problem is a little more mud on the side of the vehicle, but I think its worth it. For tires check out this website, just enter the original tire size and it will calculate the best fit for plus size tires.
http://ejelta.com/tiresize/index.htm...el=&maxdelta=2