For starters we need to decide what the goal you are trying to obtain is. A chrome wheel will be flashier in it's looks, but by nature when you chrome a wheel you make it's structure weaker. Thus, if you are doing any motorsports or performance applications, silver would be a better way to go. As far as the 17 vs. 18 that's more of a looks preference as well. E36 cars are some of the most 18 inch friendly cars that I know of, so tht's not really as much of an issue. If you like, give me a call and we can chat further about what goals we are trying to reach, thanks Aaron 800.428.8355 x395