While I love the 1911 (long live J.M. Browning) for just good old shooting fun. I prefer something with a bigger magazine and no thumb safety as a defensive tool. You should definitely buy a 1911, I think it's a great 1st handgun and then maybe buy another gun, and another, and another for defensive purposes.
If you do have your heart set on a 1911 for a first gun, the good news is you have a plethora of choices, and most of them are pretty good. You've got the likes of Rock Island and Ruger on the bottom end of the price scale, mid-price would be stuff like Springfield, S&W and Colt, then you get into the higher end with Kimber, Ed Brown, Dan Wesson etc. Lastly you have the absolutely ridiculous priced stuff like Cabot.
Across the entire price spectrum you will not find much if any difference in reliability or accuracy (any handgun is usually more accurate then the user, especially in a pressure situation). The difference is in the fine details and fit and finish. But again the good news is that many 1911 parts are interchangeable and there is a huge aftermarket. You could buy the cheapest Rock Island, and then later swap in a better trigger, or safety lever, or barrel, or recoil spring, or grips, or main spring.. whatever you want.
I'm not gonna touch the .45ACP vs 9mm for self defense debate, it's a dead horse that's been beat for decades. Except to say that a TRUE 1911 should be chambered in .45ACP as our firearms lord and savior John Moses Browning intended.