After owning an 870 for three years, which was purchased for HD, I concur with Dr. BigJimP on selection of a semi-auto shotgun for HD, but I now would go with a handgun. Both a handgun and a shotgun being preferable.
Also, if for HD and you want a little woman to use it, you may want to consider a youth model 20 gauge.
Forget all the tactical stuff for HD. The only thing I added to my 870, which came with an 18.5" barrel and an extended magazine, is a weapons light.