welcome to FT! (I am on a posting spree tonight as I had an exam a few hours ago )
I've only ever tried AZ short-haul, but what I've seen on FT is that the 777 is very comfy while the 767 isn't....As for FFPs, you need to tell us more about your flying patterns...If you do plenty of short-hauls in Economy, you need OK+. If you mostly fly longhaul business you need AF F+ rouge status which gives 100% bonus miles!!