My personal suggestions
My caliber requirements are .380 or larger in an automatic and .38 in a revolver. The new .327 may alter that, though.
Find a handgun that fits you well, you'll shoot better. An accomplished handgunner can make do with nearly anything, but it taks more effort. Try both revolvers and autos before making a decision.
Spend some money on a good belt, above all else. I like the Wilderness Instructor belt, but also have a couple good leather gunbelts. Emphasis on the "gun" part. A regular belt won't cut it for all day carry.
IWB holsters are a good choice, I use both IWB and OWB at times. If you carry a larger size handgun, don't count on it being of the "tuckable" variety. You'll look like a cossack dancer, as Clint Smith says. They do offer a bit more concealment, though, even when not tucked inside a shirt.
Speedloaders and extra mags are a must. Have a couple extra and carry at least one reload. If you wind up with a revolver and the round speedloaders are too bulky, there are such things as speedstrips, a rubber affair that keeps a reload handy but is flat. The rubber flexes to allow the cartridges to go into the chambers. If using an auto, buy a magazine pouch.
The TDI knife is a good choice, I carry one myself, along with a general use pocket folder.
If you like the grip angle of the 1911, also look at the Springfield XD series. The .45 is no larger than a 1911 and carries 13 rounds, the 9mm is slightly smaller and carries 17, I believe. Also avaiable in .40 S&W. Compact models have shorter grip frames, which helps in concealment. Too short, though, you'll give up control. It all depends on your hand size.
My personal carry set-up is a Wilderness belt ($40), Galco holster ($70) and mag pouch ($35) TDI knfe ($30) Streamlight TL1 ($90) Springfield 1911 ($500) and three magazines ($90) Total cost about $900. I did have a lot of work done to the pistol, but that was all wanted stuff, not needed stuff, so isn't in the price. Carrying a handgun that comes with two good magazines will lower your initial cost, as will buying a good $50 light instead of a good $100 light.
If I were getting set up for the first time, I'd look at Taurus (rev. and auto), S&W revolvers, Glock and Springfield autos, Sig autos, EAA autos if you don't mind large frame autos, as well as anything else that catches your interest. Don't forget to look at the used stuff, too. Some good handguns are traded in by the folks who have to change everytime a new model comes out.
A word about holsters. I like Galco because I can get one off the shelf and it's good quality. If you're willing to wait a bit (months) you can get a custom holster, mag pouch and/or belt for the same price.