Hi
First up the UK passport will not help you in Africa, though some commonwealth passports will.
I dont think there are any schools specialising in real bush skills, every area has it's own set of challenges, what is easy in one nation is a problem else where.
If you want to get in to flying in Africa, get out to Botswana, Tanzania or wherever and contact the flight companies, be humble, work hard, get the local license as fast as possible, learn the local rules. much better than a course which is probably no help outside the country where you do it.
Best of luck
Crash