Believe it or not, you can save a lot of time by figuring out what kind of trigger action you are comfy with.
As a revolver guy think about how you shoot your wheel guns.
If you long-pull them then a DAO action might be great for you. If you use your thumb like you would shoot SA revolvers then you will love SA pistols and along with magazines you can get used to safetys.
In the middle is DA/SA like Beretta's and others. First pull is long, the rest are SA short.
And then there are a few oddballs like the P-7 that are sqeeze cockers, just draw, hold onto the grip firm, and sqeeze the trigger.
Figure the trigger action out, shoot some good examples of each, and go from there. Good luck and have fun.
Oh, and there is a difference between defending the 9mm and suggesting the OP keep an open mind and let natural selection bring him to the caliber that will work best for him.
It's easy to predict common sense