Capelle,
Those are East African AAA bananas. Short of the International Transit Centre, I can't say where you might get these.
But why don't you start experimenting with commercial banana varieties that are available in your country?
I bet you're not looking at an "authentic" Ugandan recipe... if not you might as well start by experimenting around.
Just my take on it!
For my part I'm trying for homebrew with banana cultivars that I have available; including "Red", "Silk" and Mysore!
I've even brewed a reasonable stuff with the pods of the Raintree, Samanea saman!
shannon
shannon.di.corse@gmail.com