"how are you going to edit it all together? IN camera?"
The cutting and editing is on a Steenbeck.
"If you're shooting Daylight stock, I would also consider placing an 85 or an 85+Polarizer filter on the lens, but making sure to shoot a grey card at the beginning of the shot with the filter on. The 85 filter will cut down on the blue information being exposed to the film, and make your sky darker."
That's a good idea!! I should shoot some tests soon, I'll try that!
It's true that would be easier to achieve this effect with B&W stock, but I really want to stick with color film.
Thanks everyone for your help!!
Olivier