Looking to get a spray in bedliner for my truck and need advice?

I just bought a Dodge 1500 and am going to have a spray in bed liner installed. The truck has the black plastic trim around the top of the rails. My original thought was to have the bedliner installed on the inside of the bed only since I have the plasitc on top. Now I am thinking maybe I should have them remove the plastic and have the bedliner put on the rails instead (so it matches the inside of the bed). Any advice, opinions or recommendations?