For the 18x8.5, I recommend a 48mm offset. This will allow for a mild tuck if lowering.
These wheels will work well with the stock factory tires or a larger 245/40/18 for a wider tire/larger tread footprint.
This is a brief order window, so if there are any questions at all, please do not hesitate to ask. :)
Here is a Gen 2 RS w/ Pro Race 1.3's :
Or a nice Porsche (pick a color):