I second the suggestion of sfmittels; the AR-24 meets all your qualifications and is a superb handgun. I bought one a few weeks ago, and it was marked $499. The only downside to the gun is that it is so new to the market that after-market accessories are not yet available. Point of impact on my gun is two inches lower than point of aim at 20 yards, which makes it inconsistent with my other 9mm handguns and a distraction during IDPA competition. Eventually, I will find a set of after-market sights to fix the discrepancy. But beyond that, it truly is a fine gun "as is."
Boarhunter