Going to be putting a red dot on my turkey gun/slug gun. It's a Rem 870 12ga. I swap it out (chokes) for slugs or turkey loads. I currently have tru-glow sights (front and rear) and would like to move to a red dot. Any suggestions on sights? I see some are a flat "screen" and some are a scope tube type. Didn't know the difference. But would love some recommendations from peeps that are using them. Which sight and why?