Looking at Restoration Hardware's Sheer Linen Barrel Chandelier. The dimensions are 20" wide by 22" long. I was thinking of hanging two of them. My concern is what is the maximum length a chain should hang. My ceiling height is 12'. I was told that the lights can hang 32-34" above the table. Are there any "rules of thumb" when working with 12" ceilings and light fixtures? The sconces are being removed and not replaced.