Searching for the same solution. The Surly Ogre is something to look at possibly, or do what you are thinking. The challenge is the added costs and buying a nicely equiped CX bike is pricey and then adding the new components on adds that much more.

I'm thinking about saving my money by buying a Motobocane CX, and then adding the straight bar components : Fantom Cross Pro Sram Rival(this bike is spec'd at about 700 less than anything comprable locally). Adding a flat bar, Sram shifters, a larger cassette, and possibly a Stem should be in the $400 range I think.