Little Green

I searched and read all 24 posts with "spacers" as a search word. Are 17mm the correct spacers if both fronts and rears have the same wheel and tire combo and offset to make the rears "look" the same as the fronts. I love the way the front looks as it just peeks out past the fenders. I want the rears to look the same as the front as it relates to the fender. Tried the straight edge plus ruler and its really hard to be exact. There has to be a specific size as I don't want to spend time and money on the wrong spacer set. Also do the peppers use lug nuts or bolts?
Thanks
Caesar