[Redžinald Šimek] "We never work on this kind of project, i'm concerned for picture quality, because i read that both, aja and blackmagic codecs supports only 4:2:2 not 4:4:4 bandwidth."
The AJA log codec is preferred by most post houses that I know of in the US.
the LOG version it is a true 4:4:4:4 codec.
Now if FCP actually understand what to do with RGB video - I currently do not recommend to work in RGB video, if you need to work in RGB work with DPX files to maintain true rgb quality.
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD