I won't get into the 9mm Para/Luger versus 45ACP debate as there is a ton of caliber bashing you can do on both sides. Both are good cartridges when loaded appropriately.
Regarding the 1911 series, depending on your pricepoint, I would consider buying a production custom. I don't personally like Colt for personal reasons related to management (and pandering to the anti-gun crowd who blame the everyone and everything but, the idiot who used it with ill intent). I also don't like the mod's to the series 80 mechanisms and the abortion they performed on the AR-15's so they could be sole source on over priced parts. I don't like the Springfield two piece barrels and the new key lock they use on their standard pistols.
Once you start talking about reliability packages to a stock pistol, I start thinking of Rock River and Les Baer. The Springfield and Kimber custom shops build good pistols too but, for that kind of money I will take the psuedo-custom approach of Rock River or Les Baer.
For when the fecal matter hits the fan, I will take a Glock everytime. It's not that the other pistols are bad choices, they are just not the best choice for me. Absolute reliability under severe use conditions has won me over. It's not a beauty contest after all. My concealed carry in Texas was a Glock model 20 - yes a 10mm cannon for the indecisive - heavy and slow or light and fast or both

.
If I wanted a small carry pistol for when the fecal matter hits the fan, it would be a
Glock 33. It is a proven round in use by law enforcement with realistic street results to back it up as a good choice for civilian street carry.
In the end, a pistol you believe in that you can use effectively is the best choice. A solid consistent performance from a Walther PPK in 32ACP is better then anything else on the planet if that is the one pistol YOU can use effectively under stress. Whether its an ice pick, carelessly driving a car, a pocket knife, a screwdriver or, something else - dead is dead when you use the tool with such intent.