I have a Hasselblad 503cw - Phaseone p45 - Zeiss ZV 50mm set up and also a Hasselblad h3d-ii 50 with a 50mm lens.
What should I bring?
There is a lot of dust, sand, heat, water etc. there — I'd take neither — but if I really had to chose, I would take the 503cw (but also take a film back with some film, in case you have problems with the digital back).

Comments
There is a lot of dust, sand, heat, water etc. there — I'd take neither — but if I really had to chose, I would take the 503cw (but also take a film back with some film, in case you have problems with the digital back).
References :
Personal experience…