Wheel Spacers

Hey guys,
i tried searching for this, but found nothing..
i have the black saleens, with 265, 35 18;s... and i am looking to make them sit farther out... so they fit the wheel well better.. i am probably going to go with the stangsuspension ones that bolt in... i am not really sure though if i should go with the 1 inch, or the 1.25 inch ones...
anyone have any recommendations? pics before and after? or in general?
thanks in advance for your help!