Attached is the image of a beautiful walnut live edge slab that I'm going to use as a wall hanging. The piece has been kiln dried. I don't want any yellowing but I want to preserve the piece. I'm a newbie at finishing and I'm wondering which water based poly I should use? I desire a non-shiny finish, but, I've heard that some experts like to start with a high gloss coat and then finish with the desired gloss as this seems to enhance the wood. Any thought on this? Thanks so much!