Sumtoy looks like the way to go if your receiver is drilled and tapped and your gun is a dedicated turkey thumper.
Lunghit asked: "Is there a rib mount with a protective base available on the market?"
I've not seen one with protective features, but I do have a Meadows Creek rib mount on my 20 ga. 870. It is a solid mount and has held zero for the couple of years I've had it. What I do like about the rib mount is that I can interchange barrels on my gun without significantly altering zero. I can slap a 26" ribbed field barrel on the gun for dove season, switch to a canteliver scope mount rifled slug barrel for deer hunting in slug only zones, and then can switch over to the 20" ribbed barrel with Meadows Creek mount and Burris FF3 for turkey season. By going rib mount you can keep a very versatile outfit with out having to constantly re-zero your gun between barrel changes. All I do is take a shot or two after a barrel swap to verify my slug or turkey loads are still on target.