I have a 6" can light above our vanity in the bathroom I am remodeling. I want to change this can light out for a pendant light. The problem is that all the pendants I have found have very small trim rings so they would not cover the original 6" hole left when removing the can light. Any suggestions as to how to either fill this in or reduce the opening so it will look smooth? Also, should I use a "pancake" box in the new opening and how would it be best to affix the pancake in the oening?