The Milt Sparks holsters seem extremely popular among those who carry a 1911 of some sort. I have no experience with MS holsters, but if I wanted to change my EDC from a G19 to a 1911, Milt Sparks would be my first stop.
OP, it sounds like your statements concerning concealing a 1911 may be based more on assumptions than experience. I'm not trying to attack you by saying that, but if you actually have tried carrying a 1911 and had results you were unhappy with, there are a number of things you could look at to find the problem/s.
The holster itself - goes without saying that some are much better for their intended purpose than others. Holsters are an area where one really does get what he pays for, for the most part.
Your attire - there are clothes designed specifically for concealed-carry, and while not exactly critical for most people, they will often help or improve the comfort and concealment experienced while packing.
Your physique - often overlooked. The number one concern as far as
toolset goes (plenty of info available here on
mindset, skillset, toolset, if you're not familiar with those concepts). Aside from that, it's also commonly stated that proper concealment of a firearm is much easier if an individual is physically fit. Something about a muffin top interfering with a handgun's protruding grip from one's waistline.
The belt - obviously a part of attire, but it needs special mention because this baby makes or breaks the whole package. A proper gun belt can support a full-size, steel 1911 better than a bowl holds soup. The shape of one's body will play into this (remember that muffin top), but the ability of a well-made belt really shouldn't be overlooked, even if a person is just one jelly donut short of a dozen.