Have you tried an 8.5J ET41 wearing 225s?I don't think you will have issues with Tram lining on the 8.5 wheels. @Dino D has a 245/40/17 square setup for his track car.
I will be using an 8.5j et41 in the front with a 225. Ill be surprised if my tramming is made worse with 0.5 of an inch more wheel and the same tyre.
One of the options I'm considering is 8.5J ET38 with 225/40r18 tyres, when I put the dimensions into willtheyfit.com it says 9.7mm closer to the struts and 15.7mm further out, looking at the car which has 17x7.5J with 225/45 the tyres fill the front arch but the wheels sit back a little, hence why I was thinking 8J with 225s, try to keep the tyres close to where they are just bring the wheel out a bit. Should look better without affecting the steering feel.
I will of course get the geometry done after I change the wheels, feels like it needs it anyway, so a trip to Kenny Brown is on the cards.