I'm a car-free, full-time bike commuter and I want to build a new bike to handle my needs. I am having a hard to finding a frame to build my bike around and thought I would poll the internet for possible suggestions.

Criteria for frame:
Steel frame
Cantilever posts
Ability to fit at least 35mm tires, preferably larger
Intermediate between road and relaxed geometry
A longer than average head tube if possible
Braze ons for fenders
Under 700 dollars for the frame

Frames I have considered: Soma Double Cross, Surly Cross Check, Salsa Casseroll, All City Space Horse. I like the geometry of the Double Cross the best, but I am looking for other possibilities. I want a frame that feels nimble for short rides but is also comfortable enough for riding 40-50 miles at a time.

Any suggestions?