While I'm not SierraHunter, I can share a holster that has worked very well for me and for many others, for easily and comfortably concealing the Colt 1911 and other service-sized handguns. For over 25 years, I carried a Gordon Davis version of the Milt Sparks Summer Special, used it in IPSC matches, etc. It was always uncomfortable, but i just assumed that carrying a 1911 inside the waistband was never going to be a pleasant experience, and "dealt with it."
I then learned of the Milt Sparks Versa-Max 2, which at that time was in so much demand that they took 8 months to get, were rationed by the maker, and on their website they noted that if they caught you flogging them at black-market prices on Ebay you would be banned from their customer list. They were bringing twice the retail price on Ebay in 1911 models.
It is different from many IWB models, in that it doesn't put the belt loops over the pistol itself (making it even thicker.) Rather, it has extensions to both sides of the pistol, and this keeps the profile slim while spreading out the weight of the pistol across a wider area of the belt for greater comfort. The build quality, leather quality and excellence of this design are 100% top-notch!!
It has the ability to use either snap-on leather belt loops of different sizes for different belts (attaching with an allen screw), or Kydex clips if you want to use it with your shirt tucked in over the pistol for ultimate concealment. The day I got mine, I was amazed at how comfortable and effective it was. I actually took a 2-hour nap on the couch with it on -- something I could never have done with my previous holster!
The backlog at Milt Sparks has largely been cleared up now, last I heard, and these holsters are not expensive for the lifetime, top-quality product that you get. I now own several of them for various different pistols. They even make carrying a 4" Model 29 Smith .44 Mag IWB practical and comfortable! (I don't, but a friend does regularly.)
As for carrying spare magazines, I long ago abandoned using belt pouches for this, for CCW. They take up too much real estate on the belt and add to the load on your belt, things digging into your sides, etc. Instead, a local leather maker makes a "magazine wallet" that has 2 pouches for 1911 magazines (or your choice of single-stack magazines). I carry 2 spare mags in my left hip pocket, and they are so comfortable there that I don't even notice theyr'e there. The carrier has a flat, square leather outer profile that makes it resemble a wallet, if it prints at all. When I got it, I carried 2 mags loaded with 230 gr. hardball everywhere I went (even to work, where I can't carry a pistol) just to get the feel of it. By day 3, I no longer noticed them at all. With the 185 gr. JHP's I carry, it is even less noticeable than with hardball, and the mags are readily accessible. The mag pouches are inexpensive enough that I've bought a couple of spares, in case he ever quits making them.
Likewise, while the steel frame 1911 is ok to carry, using a Lightweight Commander makes carrying a 1911 significantly more pleasant.
Hope this helps!
John