Not sure what you are on about.....?
I think what you're asking is what is the biggest plane you can fly on a PPL on misionary flights?
The biggest private plane insurance companies will let you fly on a PPL anywhere would probably be something like a C402, piper navajo, beechcraft duke that kind of size and complexity. Kingairs and PC12's require CPL's and Beech 1900's require ATPL's. So don't bother with those.
In Africa on misionary flights go for a C185 or C206. They are rugged and well supported in Africa, they also shouldn't pose a problem when you are getting insurance.
PS pleease get proper training before flying here, there have been too many foreigners writing off planes here.
Speak to the Mision Aviation Fellowship, they have a base out here and I'm sure they will be willing to help you out.
Hope that helps,
Gerard.