alloys

Been looking at some alloys for the 318i, after getting a slash by some idiot in town. I am interested in the M3 alloys but was told they don't fit. Will they fit with arche work? I have the E46. I was shown some M3 replica alloys which are 19" which i was told doesn't give as smooth ride but also was told they don't rub. Is this true? Is that much space on the E46 or is he trying just to get a sale?

Thanks in advance.