I've burned through a bunch of 1911s.
S&W makes decent guns that run, but they're not traditional "Series 70s" in style and are not particularly nice. But they do run, generally.
Greg Derr guns are super nice and Greg himself is an artist and an awesome dude. But $1200 isn't going to get you half of a gun from his bench, I assume.
STI made some pretty solid guns, but they don't make single-stacks anymore. They're nice people so I imagine they'd service the older single stacks but they do seem to be trying to leave that business behind.
They're even changing their name, although clearly the messaging about this hasn't made it far yet.
Colt makes guns in your price range, and many are nice. However, if you get a bad one, which you might, you're in deep trouble as their service is almost universally regarded as awful.
Springfield makes good guns, most of which are traditional Series 70s, and the high end versions (such as TRPs) are nicer than S&Ws and Colt. Their service is pretty good, and you can just buy them off the shelf. They are right at the top of your price range. The TRP would be my recommendation. The only thing I don't like about these is that they regulate them to hit at the front dot rather than the top of the front blade. So a replacement front site may be in order, taking them slightly above your price range.
I've owned 1911s from all of the sources above. Greg Derr's is the nicest. The TRP rides my holster. The STI rides the safe. The Colt and S&W are gone and I don't miss the Colt.
Here's my thread asking a similar question a while ago.