Forget D600 - it's problematic and you get D610 with a little top up.
http://petapixel.com/2014/03/17/nikon-asked-halt-d600-sales-china-scathing-nationally-televised-expose/
http://www.digitaltrends.com/photography/nikon-issues-service-advisory-d600-owners-will-fix-sensor-dust-problems-free/