For some reason the "input your car" feature is not working right now. Using their Comparer tool, I manually put in our stock values of 205/55 x 16 and 6.5" wide rim w/ 45mm offset, then compared to 18" rims 9" wide with 35mm offset to find tire sizes of 235/40 x 18 or 245/35 x 18 (these are close to the stock rolling diameter). So with the wheels you list above, the tires will stick out either 25 or 30mm further than stock, and there will be slight speedometer/odometer errors.
I think a number of people on this forum are running 18 x 8 rims with 35mm offsets with lowering springs without problems. 9" wide is getting up there.
A 225/40 18 will give you almost exactly the stock diameter set-up and gain you a little more clearence. The tires will be stretch somewhat, I run that tire size on an 18x8 and the stretch is very minimal. The rear will fit no issue at all, the front might possibly need a little fender roll near the bolt that holds the bumper to the fender but should clear everything else.
Came across some with 245/40/18 already on them... getting a little wide for the front end I'm thinking. Might test it out and re-wrap the fronts with more narrow rubber need be.. thanks for the feedback!