Great info so far! I also have large hands, and an opinion regarding caliber and selecting the right caliber for you. My wife is a former deputy, and I have been a firearms enthusiast for years.
With big hands, be sure to fire before you buy. You might find that a slide or hammer bites the web between your thumb and index finger. Also your hands may be too big on smaller pistols that have triggers that require you to bend your trigger finger past 90 degrees to fire it.
If you find that you like the way a particular brand feels when you pick it up and fire it, and it proves reliable on forums that are specific to that pistol, buy it. A .22 is better than nothing, if you need a gun, but the most caliber that you can fire without flinching, the better of you are, I suppose. I like revolvers, they are a lot of fun, but I don't carry-never tried. BUT, in my opinion, they are more reliable than a semi auto. Any good name brand in .38+P or greater would be great, if you are confident in the capacity.
Do you prefer a double stack or single stack? Double stacks have more capacity but they can be bulky when carried inside the waste band. Single stacks conceal easier but don't have as much capacity. Also, check laws, some states are implementing capacity restrictions, etc.
A full size 1911 is tough for me to conceal in the summer, but is my choice when I can wear heavier clothes. However, when driving for long periods of time, it can be uncomfortable. I can carry additional magazines as well. Practicing with it is FUN!!!! I love 1911s! Pick a couple of them up and see if they fit you. Mine are all single stack.
I also carry a Colt .380 Government Pocketlight. It's similar to a 1911 in design and control placement, but, I can conceal it in beach clothes. It's similar the mustang with a bigger grip. I find myself wanting an M&P Shield to replace it, though (because of caliber).
For some, .40 seems snappy, and it's snappier than both .45 and 9mm in my experience. Some people don't mind. The bottom line: have your friend load a snap cap in your magazine somewhere. If you flinch when pulling the trigger keep practicing. If practice doesn't resolve it, go with a lighter round that you can fix the flinch with.
I have a Sig P229 in .40 and a nice holster, but, don't carry it (not because of the round) but because my fingers are too long to be comfortable to practice with it a lot. I prefer to carry the CZ85 in 9mm which is a GREAT VALUE if you can find it. CZ75 is great too.
I'd like to add: please get a safe of some sort, even if it's just a biometric that's bolted down. They can be had for ~100.00 and offer quick access.
Good luck, and I hope you never need to use it!