If I had to stay within the choices, the DPMS.
M1As are a joke to keep shooting accurately. If you shoot them a couple of times a year, they are fine. For heavy use, they fall apart unless you sink $3K in gunsmithing in them. There is a reason they are no longer used for NRA Highpower.
If I had my druthers, none of the above. I'd pick up a Howa or Savage barreled action, a Manners Composites stock, a CDI detachable magazine system, Atlas bipod, Badger Ordnance base and rings, and a quality 5-15X scope and deliver the parts to a well known rifle builder.