I did a quick search and came across a corvette forum. The guy posted about the same question as you did 'cept for corvette wheels. The response was that the stock wheels weigh about 20lbs and the chrome adds about 7lbs PER WHEEL... I would just factor the weight difference in your respective OEM wheels and go from there.
IMO I dont like chrome on a bike, I think dull grays, silvers blacks etc, look much better (read faster
) Chrome just slows ya down and is a pain to keep clean. Take something like the new R1 with the black wheels and red stripe in the lip... gggggooddam now that looks hot.
But thats just my opinion. If your gonna do chrome just make sure u do it right so it doesnt bubble or tarnish easily. Friend of mine had millie miglia spyders on his TL and parts of the rims were a bronze color because of poor plating.