I use Force on Force for modern Africa- but it's early days yet. I like Bolt Action too, but I haven't played it yet.
For me, FoF has a nice feel to it, which is very much related to the modern setting, while BA is more generic. I am sure BA will be perfectly good for what you want in mind, but fof has rules for helicopters, civilian mobs, cas-evacs, dogs, drones and so much more, which is why I went for it.
I wanted a rule set that felt like Call of Duty, or like watching 'Ross Kemp in Afghanistan' (if you are familiar with the documentary) and Fof delivers, in spades.