I have a 97 Mustang GT...I want to buy a new set of rims..But I also have a brake kit that doesnt allow anything smaller than I think 19's...Im not too sure why but Im thinking about to getting a new brake kit so I can get 18 inch rims...But this is besides the question....Does the front and rear rim set have to be a different sizes from each other? (Like front wheels being smaller than the rear wheels.)