Gosh darn it, open that can of worms! We're pretty much in the golden age of 1911s, so it's hard to go really wrong. A while back we talked about how the best way to think about purchasing 1911s is to draw a horizontal line across the various brands at specific price points. In other words, with a "mature" product like a 1911 (and good heavens, is it mature!), features, functions and quality is consistent for guns priced roughly the same.
The baseline for what we might think of as a "fully loaded" 1911 is a grand. The hottest competition is in the low end — $600 or thereabouts — of the market. I like Paras and STIs (FULL DISCLOSURE: Para is a regular advertiser; STI has never put a penny in any of my endeavors). The low end guns I've shot have truly been exceptional...that includes the Para GI Expert, the STI Spartan and the Taurus Model 1911 series and, surprisingly, a Rock Island 1911 (made by Armscor, I believe) that carried an MSRP of $389.
The advantage of a low end gun is that when when you decide how you really want it, you've got a good platform to work with. OTOH, guns in the $1000 range should already have all those bells and whistles.
I too have seen some really good used deals on what you might think of as "IPSC custom" or target model 1911s both online and at local gun stores. You may need to do some research on these guns...a huge number of 1911s were gunsmithed for combat-style, then practical competition (I ground a few myself), with mixed results. There was such a huge demand for these guns in the late 1970s and early 1980s, before the manufacturers began offering what are now standard features, that a lot of people who should not own a Dremel tool got into the game. The quality of the gunsmithing ranged from superb to the equivalent of a beaver gnawing the guns out of a bar of soap.
I'd check the used guns for the maker's mark, then do a little research on the Internet before I plunked down my money on a modified gun. If you can't find anything about the maker, have the gun checked by a local gunsmith who's familiar with 1911s. I always ask to see 'smithed guns at a gun store on the so far vain hope of finding a Clark or a Swenson or a Novak or a Wilson or a Behlert gun that got dropped into retail channels by an unknowledgeable person. Of course, the Internet has made it DARN HARD to pick up a jewel, because people have an easy way to research the guns!
Whichever one you get, you'll like it! Then you'll have to get a .22 Conversion top end so you can afford to shoot it!
Michael B