Which gun fits this description?

[Great-Kazoo]

I think the 43x is basically the 43 length slide with the longer grip of the 48.

Correct

[Stinky]

Just confirming the prior choices listed and adding a few comments.

The S&W 5900 family (5946)....as mentioned.
Ruger, I don't know their numbers...around P85 timeframe.

The Range Officer is a full sized 1911 (somebody said that it was Commander sized). I presently own one.

Sigs do have DAO versions.,,,very indestructable.

Beretta....I don't think so, I wouldn't recommend it. I carried a 96D, and hated that gun. The trigger is longer than a revolver's.

Not sure that CZs come in DAO

I'd get one in DA/SA....that opens up to the 5906, High-Power, Sigs, CZ-75 and a bunch more.