New rubber and wheels

In the spirit of going with a new theme with the car, I've purchased 18x8.5 +48 5Zigen FN01R-C's. I could have gone with a wider wheel, but I think 8.5 is quite perfect for the WRX. Depending how it sits on the car with the 245/40-18 (10mm's wider than my current tires on my 17x8.5 VOLK CE28N's) Dunlop Sport Z1's sit on the rim, I may purchase some wheels spacers. Size of course, dependent on how flush/not flush the wheels sit within the wheel well.