@Oyster, what about track record? (the companies you mention have been built over decades) This may be key requirement from the venture funds, hence limiting your options from the normal Aureos, TransCentury, Amana etc.
Maybe the key would be to start small myc4.com, GroFin. Or some Kenyans living abroad...
Or alternatively, approach investors already playing in the industry with a new angle but they'd take up most of the shares.