Scubapro MK25 Evo / A700 Carbon Black Tech
The casing of the A700 Carbon is a great choice for cold water divers as the casing is full metal with a hand made lightweight carbon fiber front plate, that is extremely strong and shock resistant (unlike metal, it will hold its shape when struck or dropped during everyday use).
The A700, Scubapro's top of the line second stage is combined with the latest MK25 first stage, the MK25 Evo. The MK25 has been the standard for high performance regulators and is considered the best first stage in the world. The new Evo version is now even more freeze-resistant and offers unmatched ease of breathing.
The regs are coated with a Diamond-Like Carbon (DLC) black tech coating, which makes them look incredible, but is also highly scratch and corrosion-resistant to protect your regulator from the elements.
If you're looking for the best regulator around, you have found it right here.