Rather than the Checkpoint, why not the Domane? It'll have the front IsoSpeed in addition to the rear IsoSpeed and I would think that the other the Checkpoint additions (larger tire clearance, additional mounting points for touring, etc) would actually be welcome omissions, in your case.
I found my old Domane to be super stable, I could ride no-hands on it for days, and it was very sure-footed over rough/bumpy surfaces, which was particularly noticeable when cornering. I actually moved away from my Domane because I wanted something a little more snappy in the handling department, though I briefly considered keeping it around for long, solo rides.