Picking a gun is only a tiny part of the CCW equation. I have seen so many people over the years simply agonize over the choice of firearm, weighing pros and cons of size, cost, and caliber, and then just snatch the first $14.99 nylon sausage sack of a holster they find off the shelf. A week or two later, the gun is tossed in the sock drawer as being too uncomfortable or hard to conceal.
Most folks don't realize that they need to put at least as much (usually much more) thought into how they're going to carry as they do into what they carry. Brigid has some suggestions.