Don't automatically rule out the 9mm as "not a good man stopper" There are several 9mm rounds, especially some HP rounds that are GREAT man stoppers.
First and foremost, the beretta 92 is a combat pistol. It is designed to be taken into battle, and as such is incredibly durable, reliable, and lethal. It is just as good SHTF pistol as any other in the world, and at the same time can be a great plinker for a saturday at the range.
Some things to consider:
1. Who will be shooting the pistol?
The beretta has large grips that may not be comfortable in the hands of a smaller shooter. If you have a wife or kids who may be using the pistol, you may want to consider how the pistol fits their hands. Most people like the hand filling nature of the beretta grip, however some do not. If grip size is a consideration, perhaps look into the Vertec grip. It is a smaller grip built onto the same pistol, so if you or someone else who will be using the pistol is not comfortable with the standard style grips, look into the Vertec. Another thing to consider with your shooters is the caliber. The 9mm's recoil is significantly more forgiving than some larger calibers. This will make the pistol much less of a chore to practice with, and therefore the more you and your family practice with it, the better prepared they will be to use wel it if ever necessary.
2. What will you be using the pistol for?
I know you said it would be primarily a plinker, but it wouldnt hurt to think about what else you may use the pistol for. The 92 is a FULL SIZE pistol in every regard. It has a 5" barrel, full size frame and holds 15 rounds (unless you live in one of our more communist states). This makes the pistol LARGE and HEAVY relative to some other pistols. That means that the 92 might not be the best choice for CCW as its large size would be tough to conceal, and its weight will make itself known after a day of carrying it.
3. How often do you want to shoot/how much do you want to spend to shoot?
The 9mm is a great round to have your gun chambered in. It is a great self defense round (dont let any .45 guys tell you otherwise) and is VERY common and VERY cheap (all things are relative). If money is a concern for you, the 9mm is definately the way to go. A 9mm round runs from 9-11 cents per shot, whereas as .40 can go from 13-18 cents and a .45 usually for around 20 cents. You will get a lot more bangs for your buck with 9mm than you will with .45. As I stated in point 1, the more inclined you are to shoot the pistol, the better you will be with it and the more able you will be to employ it effectively.
Typical cost for a new 92 should be around $550-$625. It will generally come with a hard blue case and 2 15rd mags (or 10 if you are in any of our people's republic states).
Good luck and I hope you are happy with whatever pistol you decide to go with.