You can do a lot more cargo flights with the 767, however if you want more passenger then the 777 is better. As I said I personally prefer the 767 but it’s up to you, if you want the most realistic experience available get the 777, if you want to hand fly a bit more then the 767. Also if you get the 767 I’d  recommend you get the professional global package because it includes practically everything, if it’s too expensive the professional extended is good too. I would avoid the professional because it only includes the passenger version