That offset is not going to be flush. Using that offset and a 10mm spacer will get your pretty close to flush. That would essentially be the same as having an 18x9.5 wheel with a +28 offset.
Using that page, you would want a wheel that puts you around 92-95mm of poke to achieve a flush look. You might be able to achieve a flush look on those wheels by going with a wider tire like a 285/40/18. The tire would then appear flush, but it would likely stick out past the wheel itself a bit.Did and didn't understand the page, that's why I'm asking