I have 215x45x16, on 16x7's ... I went to the tire shop, and I asked them what was the closest thing they could give me to match the diameter of the stock wheel/tire, and they said 215's would be my best bet. Also, the Kumho 215's have a small lip that sticks out, and it kinda protects the wheel, which is nice...

As far as I know, performance benefits, depend on what you are going to be doing with the car....?