Happy to help OP. If you are looking for a "perfect" square fitment, then we highly recommend going with a 9" wheel all around. We recommend going with the 18x9" ET30 (or ET31) front and rear, paired with 235/40-18 or 255/35-18 tires. You are correct in that KW suspension do limit inner clearance. However, our 18x9" ET30 wheels are a great solution as they do provide great clearance even with KW's.
If you would like to get a complete picture of what fitments can work for your car, you can check out our comprehensive fitment guide
here.
