Personally, I'd go with the 9000 for a 9mm (that thing's great!), or the Cougar as a CLOSE second, though it is only available in 9mm or .40S&W. No plans for the .45 as far as I know.
As a side note, your budget is awfully close to a real nice 1911 (for instance, a Springfield GI or Mil-Spec), and those are usually very easy to conceal. I've seen the parkerized GI for as low as $419. Just a thought.