You can't expect Z1 to give you reliable information on wheels they didn't sell, there's just too many wheels on the market to know them all. Z1 looked and mis-judged, no one's perfect. Just spend the extra 100$ on spacers and studs yourself, what the big deal? You've invested so much in the car already.
You need to do the measurement your self and engineer the system for your components. You just might need a 8mm, 12mm, 14mm or some other spacer size. Who knows?
