If those are the only two options, I would get the Razer keyboard...I personally use the Blackwidow Ultimate and I've had no issues so far. Mechanical keys are great
Though the Rosewill Mechanical Keyboards are pretty nice as well, my brother uses the Cherry MX Black ones.
Though as LogiCal stated, the Corsair K series Keyboards are great! My friend has one and I love the switches on those more than Blacks/Blues.