I would go with a pump. I have an 870 and a 500, I like them both equally. Functionally they are equal. I would give the edge on appearances to the 870. The 500 would get the edge in the home defense section though because they make a lot of options for the 500. You're already shooting the .300 wsm so the recoil is not an issue. So I would go with a package deal on either the 500 or 870. I would get the package because that will give you everything you need from home goose to deer.
-Jake