That's not entirely accurate, you could put the same size tire on the stock wheels, and rotate them for that matter. It would just be inconvenient to have to keep track of as the width of the stock wheels are different front to back. The fronts are like 5.5 and the rears are like 6.5 or something like that. You'd be juggling different size spacers and locations all the time.
Most aftermarket wheels are 7" width, then you just have to choose your offset. Most of us are running 5+2's which will put you at about 55" width. Some have went with 4+3's which spreads the stance to like 57". Depends how wide you want to be? You'll need some 1" spacers for the rear regardless, if you want to keep an even track width front to back.
Width of tires are going to be your choice too, 9's, 10's or 11's. Most go with the skinny's.
A good starting place would be four 12" 5+2 4/100 wheels of your choice. 14" are an option as well, you'll get a rougher ride but may find more tire choices. Don't forget to get splined lug nuts, 12mm x 1.50, stockers won't work. Two 1" 4/110 spacers for the rear. Then the 12"/14" tires of your choice.
A lot on this subject is personal preference but that's the short version and should get you going.
