Gonepostal,
UGA and others have touched on the most important aspect, which is training and mindset.
You have acknowledged their thoughts, so I won't repeat what they have said, other than to say I agree with them.
With that being said, I highly suggest you find a range near you that rents handguns and try out several different options.
Some of the others around here can correct me if anything below is inaccurate:
Sounds like you have focused on autoloaders, so we'll leave revolvers out of the discussion for now.
With that being said, you have some options as to how they are constructed, which greatly effect comfort when carrying, rust resistance, capacity, etc.
Polymer
Polymer guns are my favorite. They have a polymer frame, that can take a lot of abuse and show little signs of it. Most polymer frame guns have a high round capacity.
Some of the more common Polymer guns are:
H&K
Great gun. More expensive, but expense doesn't appear to be an issue here. H&K features ambi controls, if you are a lefty. Their 45 is a very popular choice.
Glock
Glock made the polymer pistol popular. The Glock 21 is a good choice in .45cal. Most people are either hot or cold on the Glock pistols. Newer generations have a molded grip that doesn't fit some people's hands. Other people complain about the grip angle, saying it hurts their wrists when firing. No matter the opinion, it is hard to argue that the Glock is one of the most reliable and popular handguns for personal and executive protection.
Smith and Wesson
Smith has a new polymer offering in .45cal. The M&P45 (military and police) is a nice gun. The M&Ps have interchangeable backstraps that help you custom fit the palm swell to your hand. These are very very comfortable guns, but their reliability has yet to be proven because they are fairly new on the market.
There are lots of other choices out there for polymer pistols. To name a few without going into detail:
Walther P99
Beretta PX4
Sig Pro
Springfield Armory XD (very popular 45 version)
Aluminum/lightweight metal
Then there are the aluminum and lightweight metal-framed pistols.
Sig Sauer
Sig probably produces one of the most popular metal-framed gun series, the Classic P-series. P-226 is available in 9mm and 40cal. The P220 is similar in size and weight, but is a 45 caliber. These pistols are very popular among executive security personnel as well.
Smith and Wesson
Smith has some metal framed guns that are decent as well and can generally be found at reasonable prices.
Smith also makes a nice line of lightweight 1911 style pistols in .45 that are reasonablity priced as well.
Springfield Armory
SA makes great 1911 style pistols. I own two and have been very pleased. If you're interested in a 1911, be sure to check out SA and S&Ws.
Beretta
The Beretta 92 (similar to the standard military-issued M9) is also a good duty weapon. I don't have any personal experience with it, but it's hard to argue with all the police departments who are using this weapon.
Heavy Steel/Stainless Steel
Then there are some frames, most notably the mil-spec 1911, that are heavy as hell. If I'm carrying a gun that is heavy, it will be a 1911. No further on this topic.
So...there's a shallow primer on handguns.
Now...you need to know about trigger selection, which is why my first recommendation of finding a range that rents is so important.
Trigger actions
There are several different types of triggers.
Glocks and most polymer pistols, generally speaking, are DAO, meaning that you have a consistent trigger pull from the first round to the last round out of the tube. These pistols do not have hammers, they are striker fired.
SA/DA (Single Action, Double Action) trigger is common on many of the aluminum and lightweight-framed pistols. These handguns have hammers, and can be manually cocked, placing the pistol in Single Action status. This means that the trigger pull is very light, when in single action. Typically, these pistols are carried with the hammer down, which allows for a very long first stroke of the trigger (double action - because as you pull the trigger, you are forcing the hammer back at the same time). When the round fires, the action of the slide automatically cocks the hammer for the next round, which leaves the gun in Single Action from the point forward (or until the gun is decocked.)
1911's operate in Single Action. This means that the hammer must be cocked in order for the gun to be fired. However these guns have two safeties to negate the danger of running around with a cocked gun. They have a grip safety, which is naturally engaged when you grip the pistol. They also have a thumb safety, which needs to be deactivated manually before the gun can be discharged. Standard carry method for 1911's is "Cocked and Locked," meaning there is around in the chamber, the gun is cocked, and the safety is activated.
Since the hammer on the gun is already cocked, the 1911 has a short trigger all the time - from first shot to last. Personally, I believe the 1911 has one of the best triggers of any handgun available. But you have to feel comfortable with the method of carry. Some folks do not.
There are so many variables when it comes to choosing a firearm. The best thing to do is get your feet wet by handling them in a safe environment and firing the ones that feel the most comfortable to you.
Whatever you choose to purchase, be sure to buy lots of ammo for practice. The best handgun in the world is useless if you can't hit anything with it.
Hope these semi-random thoughts are helpful.
Good luck to you, friend. And welcome to the High Road.
