The primary (as in cruiser ready) HD gun here at Festugn Scout is a 12ga, formerly PGO, Maverick 88, that now sports a Mossberg wood stock (but still has the black synthetic fore-end) and a Mossberg trigger group, meaning no safety.
We've a couple of other Mossberg's. I use a 500 with an adjustable comb (and several different barrels) for hunting. My wife and daughter have 20 ga 500's that they use for clay games and hunting. I've also got a 9200 that I use for clay games and the occasional upland hunt. If I ever get the bug to hunt waterfowl, I'd probably use the 9200 for that. (Less recoil then a pump, O/U. or SxS.) All have gone bang everytime I've pulled the trigger, unless I did something wrong (like not loading it, leaving the safety on, short-stroking it, etc.)
I've narrowed my search to a Mossy 88 Security 18 1/2" model 31023 or a Mossy Special Purpose Persuader/Cruiser 18 1/2" model 50411 for home defense. There seems to be approx $175 difference in price. ($150 vs $325) Worth it or no?
Both are good guns and can do the job if you do your part.
If you're only going to use it for HD then go with Maverick and spend the other money on ammo....BA/UU/R.
If you're going to being using it for other things, like clay games or hunting, go with one of Mossberg's combos. Still buy lots of ammo and BA/UU/R until the gun becomes part of you.
The Pistol Grip Only kit is pretty much worthless, first) you can't properly point the gun, second) follow-up shots are not as easy as with a full stocked shotgun, and third) operating the Tang safety is a real PITA.
If you're going to go with the 500, I'd go with a either one of the wood stock 6 shot models or one of the 8 shot models. FYI - all Maverick 88 and Mossberg 500 6 shot models can easily interchange barrels as long as they are the same gauge.
Again, both will serve you well, if you invest the time in the gun (shotgun classes are good idea to develop good habits and refine skills) through practice and training.