I hunt ducks and pigs with my 500, and I can tell you I can get 3 rounds off very fast- with the factory forearm. Keeping the stock as-is gives you something to beat the perps head to a pulp if you run out of shots, or the gun jams. My 2 cents.
For home defense, I would not put a light or a laser on it, tritium sight if anything. The light and laser give away your position, assuming it's black inside and the perp is moving towards you. If the lights on, you don't need them.
One thing to remember, try shooting 00 buck with a short barrel at 10 yards, and the pattern is only the size of a softball. I blown holes in wild pig's rib cages like that, I can tell you. You still have to aim it to hit what you're wanting to knock down.
I hope and pray you never have to fire that weapon in fear, or anger.