New surly preamble drop bar? Or slightly used Cannondale al 2

If you’re already willing to spend $1200 then you have way more options available.

Marin and Kona have significantly better options around $1000 for drop bar bikes. More specifically Marin, they have steel and aluminum options within your budget.

With that said, that Cannondale gives you a lot better components than the Surly, Marin, or Kona options. I’d personally take the Cannondale. Shimano Tiagra groupset, hydraulic disc brakes, aluminum frame, dt swiss wheelset. All better components than whatever you’d get with anything similar to the Surly. The Cannondale is an endurance road bike compared to the surly or even most drop bar options from Marin and Kona. It will be capable but not necessarily as good of a touring bike if you wanted to backpack or run 45c tires.