Hi! I've heard good things about Habari Node[1], and Angania[2] is a startup working on Nairobi-based hosting. That said, I and most developers I know in the region host internationally. As others have mentioned latency is usually a bigger problem than bandwidth. Happy to take a look at your site if helpful (just add it to the form).

[1] (http://www.habari.co.tz/) [2] (https://angani.co/)