BBS Rms with clipper kit, hot wide should i go?

I want to have the lips of the wheels flush with the fenders. It seems like i would need the lips to be 1" wider in the front and 2" wider in the rear, but i'm not sure how the sizing is set up. If i ask for the 1" lips will i get the same size as the lips from the factory or will i get lips that are 1" wider than factory? ohh and if ur running htem please tell me what size ur running.