I just picked up a used 870 Marine Magnum. It has the thumb hole stock with a cheek piece that prevents me from using the standard front bead. I kind of like the stock but I would be OK going back to a traditional one also. There is no rail or rib. It has a tapped receiver so I can add a rail. Ideally I would like an adjustable rifle style rear sight and the accompanying elevated front. I already checked Brownells and Midway so does know of something like this or have a better idea/advice? I would like to keep it "clean" which rules out a scope but a holo sight might be an option as a last resort.