18 inch wheels on m sport 3.0d

[Chris61]

Hi there, i currently have 20 inch wheels on our m sport x5 and i purchased a standard set of 18inch wheels with runflats for winter use and driving out to the alps skiing. I purchased chains for the 18s and havent fitted winter tyres. The wheels did look strange with the m sport arches so i wonder if someone can advise what spacers i should fit and where i could get them. Also any advice on where i could get winter run flat tyres in uk would be helpfull. Finally i am thinking of haveing the wheels powder coated, and wondered what colour you think would look best. Our car is sapphire black. Thanks for your help, regards, Chris.