Since surly is designing their bikes, I really doubt that you could buy one directly. I think that the crosscheck complete is a good value, especially at some of the sale prices on the net. The volpe comes with brifters (expensive) and the x-check comes w/ barcons (relatively cheap), so people say the the volpe is a better deal.
The surly comes with a salsa handlebar, salsa chain rings.. both come with shimano hubs (deore vs tiagra) and alex rims. Surly is double, Bianchi is triple. I'd say that the components are sort of a wash - w/ the bianchi getting the nod for the brifters (if you want them). Now, Surly is a much more expensive frame (whether you think it is better or not is up to you), but I wouldn't put the value of the volpe frame as high when comparing the 'value' of the build kit that it comes with. Also, Surly is great with customer service. I've asked a few questions about a frame and gotten a same-day return email with advice from an experienced cyclist.