turboitis

I am currently searching for rims to put the factory 225/40/18 tires on. The 18" rims that came with the sport package currently have my snow/winter tires on them and will be dedicated to that.

So I am having issues with trying or wanting to fit different offsets on the car, haven't bought any rims yet but was wondering if anyone has put or seen or has input on what will fit etc.

18" x 8" rims will allow the tires to stretch on them, (stock rims are 18" x 7.5")but it is the offset I am unsure about. I hear the stock offset is 54mm and so 45 mm offset seems ok but 35 mm may be to much?

Any help or direction would be much appreciated, I want to do this in the next two weeks, it is getting too warm to run my soft winter tires after that.

Thanks