The major concern with using an 11 speed crankset with 10 speed is the .6mm narrower spacing on the 11 speed chainrings. Meaning there's less space between the inner and outer chainring. This could be an issue with the wider 10 speed chain.
The possible solution would be to run an 11 speed chain (works fine on 10 speed drivetrains) a la KMC X11SL. Don'tknow how well it would work.
Otherwise, if you want a Campy crank, try to find the older 10 speed Super Record crank, or a Record crank in 10 speed variety. After that, you're stuck with either FSA or SRAM.
There's also the hard to find DA 7800 carbon crank, but that's not exactly weight weenie - I believe the forged 7800 crank is lighter, let alone the 7900.
I thought THM had BSA cups as an option? http://fairwheelbikes.com/thm-clavicula ... -2812.html