Re: Looking for a Conceal Carry
You have gotten some excellent advice so far on this question. I'll just add that what is golden for some may be a pile of crap for others. In other words, until you get the pistols you are considering in your hands (and it is even better if you get a chance to actually shoot them), you'll never know what will be best for YOU.
Some guns look great on paper and on the spec sheet, but once you have them in hand are anything but ideal in terms of how they fit you, the operation of the pistol, etc., etc.
Also, don't make the mistake that many people make about caliber selection. Bigger doesn't always mean better. In fact, with modern personal defense ammo selections, a 9mm makes an adequate concealed carry option even though it still won't have the same terminal performance of something in the .45acp range. It all comes down to what you are most comfortable with, what you can control adequately in a self-defense (or competition) setting, and deploy effectively in a situation that is completely unlike plinking at your local range. Whatever you get, train with it, train with it some more and when you think you have trained enough...yep, you guessed it...keeping training. Don't be one of those people who ends up causing more harm than good in a situation where you have to actually use your CCW.
Finally, as for the size of the pistol itself...that will depend almost soley on your size and ability to conceal it. While there are people out there who could probably conceal a full-size, double-stack 45acp pistol, most people will need something smaller. Again, how much smaller depends on you and your body type, how you plan to carry (OWB, IWB, SOB, etc.), the clothing you plan to be wearing while carrying, and so on.
As for the Glocks...they are excellent pistols well-suited to the personal defense/concealed carry role. The problem is...if you settle on the .45acp you only get to chose between the full-size 21 (or 21SF...neither are easy to carry concealed) and the sub-compact 30 and 36SF. If you go with a 9mm or 40S&W, you can get into the compact models (the "tweener" size pistols) like the G19 and G23.
Just some food for thought. Good luck in your search and let us know how you are progressing.