Pick a Mossberg, Remington, Benelli or other good solidly built shotgun that fits you, you like, and you shoot well. Practice until it is second nature, location of the safety, full stroking the pump if that is what you choose etc.
Ithica 37 defense or Mossberg 590. I think the 870 is a better shotgun than the 590 for hunting, but the safety on the 590 is more accessible (especially in stressful situations) and for that reason I think the 590 is better for home defense. Make sure it is cylinder bore
