I have a 38 inch and run 177.5 Dura Ace cranks with a full Campy record drivetrain and love it. I would have used 180's but my other road bikes are 175's and I wanted to keep them consistent. I do use 180's on my single speed mtn bike though.
I think you're right about the Dura Ace cranks being the best out there at the moment, although if Campy carbons came in 177.5 or 180 I would have still used them, just cause I'm a die hard Campy fan, and I think cranks stiffness is often overrated.
BTW. Campy's are available in english and Italian threading, as are most bb's aren't they?