you need to consult a source like http://www.lyngsat.com or http://www.satcodx.com to determine these things:
(1) which channels you would like to receive (they contain full lists, including genre and language)
(2) which sat(s) they are transmitting from
(3) which tranponder(s) on the sat(s)
(4) the footprint(s) of the tranponder(s) (ie which part of the earth's surface is covered by the beam - does it encompass Niger?)
(5) the strength of the signal across the foortprint
(6) the dishsize you would need to receive that signal adequately. See also http://www.satellites.co.uk/scripts/dcforum/DCForumID23/10.html
To dertermine the kind of LNB & receiver you would need...
(7) the format of the signal(s) (analogue, digital)
(8) whether it is MCPC or SCPC (multiple or single channel per carrier)
(9) which band the signal falls into (C-band is the low-frequency range, Ku-band high; for C-band you need special LNBs and much larger dishes)
(10) what kind of video and compression technology is used (is it Pal? NTSC/ Is the compression DVB-norm, Powervu/ etc.)
(11) what kind of encryption technology is used if any (is it FTA=free-to-air? Is it soft-encrypted? (ie requires a particular kind of decoder but no CAM/card). Is it FTV=Free-to-view (ie requires a card but no subbscription). Or is it a subscription channel? If it is the latter, is it encrypted under Irdeto, Seca, Conax, Videoguard, Euurocrypt, Videocrypt, Nagravision, Viaccess, etc etc etc. That will determine what kind of CAM and card you need.
This all seems a little overdone but these are really the questions you need answering. There are simply too many different formats and possibilities to be able to say , oh yes for sat tv in africa you need xxx.