First question, is your wife okay with having a gun in the house? Is she willing to train to use it safely, and effectively to increase her comfort level? Do you have an ironclad plan for the twins to have zero access to the gun now, and when they start toddling, or walking around?
Remember, if you get into the revolver business, a revolver's gasses will hurt someone if their fingers extend to the working end of the cylinder. This area of "no man's land" is important to understand.