The size of the wheel doesn't really matter.
7.5 et40 with 225s I have genuinely no idea how you are rubbing.
At the front of my car I have 225/45/17 with 17x7.5 et 56 and at the rear I have 17x7.5 et 36 and have no rubbing at all. 225/40 is basically the same rolling profile so will not adjust the rolling diameter and thus the height which is not going to change the rubbing.
An 18x8.5 et35 will rub to high hell. You'd want an et40 at the least and if you do that, you need to do the front arch screw mod and run 205 tyres.