I'd just stick with 215/35/18, looked at 225 for the same reason on rear but as stated I think I'd have been changing them again.
R888 have a solid tyre wall and on my evo the ride was terrible, good for the track yes but after 2 track days they were dead and expensive to replace, I've gone for toyo proxes T1R for the cossie, good price and excellent all round tyre also very good on the track including Nurburgring, where other tyres failed the toyos did not.