Any reliable shotgun of at least two shots capacity is a great HD tool. The add ons are nifty, but not essential.
Before going for all the gadgets and gizmos, buyamessa ammo and hie thyself out to the range,frequently. After burning up a case to six, you'll have,A,much better control, and B, a better idea of what actually is positive and what is not.
Anyone who has spent more on bell and whistles than ammo should think about his/her priorities.
I must admit that my HD 870 has a short but impressive list of add ons, but some of my best work has been done with stock duty weapons.
And consider this, the FBI database on shotguns indicates one shot, one neutralized perp. If you're attacked by a group, backup may be what you need, not a coupla more rounds in the extended mag.