..although I never considered a pump shotgun...Food for thought..
Warning: Slight ThreadJack here. But since the OP mentioned not considering a shotgun I'm going to walk out on a tangent here.
I'm not going to say that a 12 gauge is a magic wand that makes bad people simply go away. What I will say is that it's one of the only weapons easily available for us to purchase for a reasonable price (usually under $500 for a GOOD pump action) that dramatically improves the stopping performance of "Bad Hits"
If in the heat of the moment I fire my .45 ACP twice and put one round in the wall next to the BG, and one round in his bicep. Chances are if he's even half determined he's going to keep coming. If I put one shell worth of 00 Buck in the wall next to the BG, and put a second on in his bicep. Chances are he's going to need a lot of surgery to repair that arm. And unlike a single .45 caliber hole. he very well could bleed out of that wound.
one shell of 00 buck contains.... 9 .32 caliber balls iirc. At "in home" distances the pattern is usually 2" or so across (meaning aiming is important) a 2" circle with 9, .32" holes == bad for the body.
[soapbox]
That said..... Any Handgun, Rifle, or Shotgun you intend to use for self defense in the home, should be accompanied with a good amount of defensive weapon training. Determine what gear you intend to use for self defense, and then make your next priority quality training.
[/soapbox]