If considering East Africa, I would always recommend Tanzania. Getting a licence conversion is reasonably easy in TZ, and then that should make it easier to to convert that to the other East African Community countries. Kenyan CAA is corrupt at sh@t, or at least used to be, and that is not in favor of you - unless you are willing to pay ridicules amounts of money for an otherwise useless licence. The flying in the East Africa and Central Africa is really awesome, and probably some of the best bush flying around, with a combination of dirt and mud strips and the occasional concrete/tarmac field.
Good luck
