There are .380 ACP rounds that push 250 lb-ft of KE which is squarely in the .38 spl wheelhouse (snub nose), but of course the bullet is lighter.
If the only pistol you can own is a .380, well then, as others have stated, go with the one that holds the most rounds...Like a Browning or Beretta M84(?). In America the .380 is viewed as deep concealment so the most popular offerings are sub-compact with generally 6 shot magazines.
If you're thinking home defense against intruders, robbers, or marauding bands then a 12 gauge shotgun should be on your list of "must haves."
A great many people will tell you to use buckshot of one size or another because it "spreads out"...and all you have to do is point. Well, at IN-HOUSE distances shot charges only spread about 30mm per meter distance from the muzzle. In a 4-5 meter room this means 12-15cm which by no mean! means you can just "point" and be assured of a hit...and it gets MORE important to aim the closer your target! Also, all those pellets seem mighty impressive when you shoot something up close and get the full effect of the "shot charge" while still in close proximity, however, at 20-30 meters, those 9-12, .33" buckshot pellets will have separated far enough so that only one or two may strike the intended target and this means VERY LITTLE KINETIC ENERGY is delivered! A "shot charge" that delivers 1,500 lb-ft of kinetic energy at the muzzle, only delivers 125 (12 00 buck) to 166 (9 00 buck) lb-ft PER PELLET once the charge has opened up. It only goes downhill from there with smaller shot sizes. This is WHY so many people are STUNNED when they shoot someone with a shotgun loaded with "buckshot" (especially #1 buck) only see no effect! A thick leather jacket can sap a LOT of energy from a round buck pellet that's impacting with no more force than a .22 Long Rifle bullet (except the .22 bullet has a smaller frontal area and so will penetrate better).
The ONLY thing to stoke your shotgun with is SLUGS...slugs work ALL THE TIME whether the person is 2 meters away or 50! A slug delivering 1,500 lb-ft of kinetic energy at the muzzle DELIVERS it all in a near 20mm diameter, 28 gram monster hunk of lead, and if you can obtain sabot slugs they deliver more still...plus, sabot slugs can shoot accurately to over 200 meters which at least puts you on a better footing if you're facing someone with a rifle.
Most people are surprised to find that rifled slugs fired from a smooth bore are capable of 8-10 cm "groups" at 50 meters, but since you should only be shooting slugs anyway...go ahead and mount a RIFLED barrel and you're basically shooting a very powerful "rifle" that has tremendous close-range terminal effect, and requires no ammunition "choices" based on whether someone is up close or way out there.
I would personally advise you to choose an AUTOLOADING shotgun...if you can get one, the SAIGA-12 is choice number one...it functions just like an AK-which means as reliable as a human machine can be made to function, and it uses detachable box mags which means you can lay-in a supply.
If limited to "traditional" shotguns look for something like a Mossberg, or Remington semiautomatic...if you can get it, go for the Mossberg Model 930 chambered to shoot 3.5" (9cm) shells which means SLUGS up to 43 grams! These rounds are capable of generating close to 3,000 lb-ft of kinetic energy, fired from a gun that can shoot several VERY quickly. In that case you carry your spare ammo in a simple "bag" you can sling over your shoulder and run...so each time you fire you train yourself to recharge the gun - "top it off" so to speak.
If you want or think you need an optical sight the ONLY choice is a quality, "armored" red/green dot with laser, or a laser separately. The dot sight gives you parallax free, EYES OPEN HEAD UP target acquisition. The very best laser to buy is the Laserlyte "Centermass" that projects a large center dot with a ring of smaller dots around...VERY easy to see even in daylight and much faster to acquire than any single-dot system.