The FSA Metron 5D is pretty popular and is used on the Bianchi Oltre XR4 amongst other aero bikes. Not cheap though http://www.wiggle.co.uk/vision-metron-integrated-5d-carbon-handlebar/ I think you can get it at Bike24 for 449 Euros
I'm looking at buying a Bianchi next year but there's no way I could justify that kind of money for a cockpit (even if it is available in Celeste). Weren't Canyon talking about making their aero cockpit available at one point?