I am not sure if this is where I am to ask a question or not...but here it goes.The lady who is doing my son's wedding cake is suggesting that we use a 18 inch cake plateau. The bottom tier of cake is 12inches and it will sit on a 16 inch drum. Does this make sense? Will it look OK?

I am also wondering what the difference is between a nickel plated cake plateau and a silver plated. Which one will look better? Which will last the longest

Help ....thank you.