What offset is correct to allow most largest lip on rim and still be drivable. What is also the widest 7",8",9" for front rim and rear rim. I'm looking at 16"x8" with 40 or 45 series tires on front, and16"x9" with matching 40 or 45 series tires on back. Will 20 offset in the front and 15 offset in the rear work.