the easiest way to do this is to contact the company who make the original reader directly (ICT or coinco or whoever) and tell them the model what you have in the JVL now... and they will match you up with a african money acceptor of the same designation.
otherwise, a "Pulse" type bill acceptor could be made to work with this system with some modification... but if you are inexperienced, it may be better to go the first way i mention.