I sure hope someone can help me with this question. Currently I have a Moen brand showerhead and handle in my son's shower and would like to replace it with a Kohler. Is this something that can be done or would the valve that is in the wall have to be replaced? In other words, do I have to stay with the Moen line from here on out? The shower is an acrylic unit, so what has to be done? Thanks to anyone who can explain this to me in very simple terms.