I am currently selling a rather nice 'K' series SMC Pentax 1:1.2 50Mm.
Yep, the beautifully engineered and built one with the big hole in it. I think it would work superbly with the excellent live view on the D600.
It is such a nice bit of glass that I'm having mixed thoughts about parting with it, although the $'s will come in handy to build my Nikon kit.
I am toying with the idea of keeping it and getting something like the Fotodiox adapter for use with the D600. This particular adapter has a built-in 1.4x Multi-Coated Focusing Correction Lens which is removable for Macro Photography.
But, and ain't there always a 'but', assuming the adapter is 10-20mm thick I'm figuring that I'll finish up with a cropped 60-70mm lens and lose at least 1/2 stop of light.
If my assumptions are correct, it sort of defeats the purpose of the exercise as my 50mm f1.2 is now a 60-70mm f1.4 or thereabouts.
Maybe I'd be better off with a Nikkor AIS 50mm f1.2 instead.