i am looking into getting aftermarket wheels and tires for my stock height 99 silverado. I have just a couple of questions about the rims, i have the tires all figured out. the wheels i am looking into getting are the KMC XD series addicts but there are two options one has a -12 offset and one has a +18 offset. which one would be better,i want something that sticks out just a tad but not to much. and will the 17x9 wheels fit properly, depending on the offset?