I built a CX frame into a disc brake-equipped winter commuter / bad road bike. I wanted to do it cheaply, so I bought an aluminum frame with a carbon fork. I was really surprised at how compliant the ride turned out to be... The longer wheelbase + larger tires (700x35's) made a huge difference.

My "normal" bike has an 853 frame, so I definitely am a steelie... Just thought you should know there might be other options out there for you.