I looked long and hard at my needs/requirements and decided to go mainly with the .22 magnum. Yeah, not the choice for everyone. But I looked at the ballistics and videos of it's performance in Gel blocks and even read a compelling story written by a man who was shot point blank with one. I don't live in a high risk area at the moment. It also allowed me to stock up on ammo at an affordable price. (In my humble opinion) I do have a Ruger sp-101 in .327 for home defense and also a couple Nagants which are fun. But the others are basic .22 magnum revolvers from Charter Arms and two mini revolvers from NAA.
I can put the NAA revolvers into a pocket but they also make little holsters for the belt and ankles.
I even bought a couple .22 magnum rifles to go with them.
Small 30 caliber ammo cans will hold an even 1,000 rounds of .22 magnum ammo.
Again, not for everyone but for me it was a good choice.
PS- If your a bit older you may also consider another choice (where it's legal) in a sword cane from Cold Steel. It's a quality product and if all else fails it's better than a rock. I don't need to use a cane yet but I keep it in a corner of the bedroom as a "just in case/if all else fails" weapon