I would also like to buy one from an American company made in the U.S.
Among the major makers, that means Colt, Kimber, or S&W. S&W has the external extractor, so on your criteria they are out (they ARE good guns, though).
I'd go used Colt. A used (in decreasing price order) Series '70, Series 80, 1991a1 should all run from $600 to $750 in excellent condition. All of them are close to the original design for all intents and purposes. Don't get hung up on the Series 80 firing pin safety - it's totally reliable, innocuous, and you really don't know it's there.
A current new 01991 (mentioned above) is a great gun, too, just not polished like the Series '70 or 80 from those decades. A new one has a $700 handle on it, a used one in the $600's.
I have owned a variety of 1911s in the last few decades and the ones that give me the greatest satisfaction and quality for the dollar are Colt's. I even bought another one this morning, in fact! (An 80's Combat Elite). Other guns work fine, and others are well made. But there IS something about a Colt and if you are looking for a special "authentic" one, I say get a Colt.
If you're $600 limit is firm, look hard for a 1991a1 in Parkerized or Blued from the '90s. They are good guns and go too cheaply as they are under-appreciated. $500 to $550 is a good price for an excellent one of those.