With 245/35r18, I would say 8.5"-9.5" would be the sweet spot. Do you like the fat wheel look? If so, I would go 18x9 or 18x9.5; these widths are going to require a pinpoint accurate offset choice, in order to avoid rubbing when a 245 tire is mounted to them.
Since you are not tracking your car, rim protection may be a factor to consider. Curb rash sucks, so a narrower wheel will be better protected by a 245 tire; an 8.5" wheel would have okay rim protection, but 8" would have great rim protection from a 245 tire. A 245 tire on an 8" wheel will result in steering that is a bit numb/vague, due to the slight lack of sidewall support, so it's all going to depend on driving style/preference.
Since you are not tracking your car, rim protection may be a factor to consider. Curb rash sucks, so a narrower wheel will be better protected by a 245 tire; an 8.5" wheel would have okay rim protection, but 8" would have great rim protection from a 245 tire. A 245 tire on an 8" wheel will result in steering that is a bit numb/vague, due to the slight lack of sidewall support, so it's all going to depend on driving style/preference.
