how good they are and where to get them in nigeria
It appears that the Faculty of Agriculture, Department of Animal Science, Nasarawa State University, Keffi, Shabu-Lafia Campus, Nigeria has done some work on the Sasso in Nigeria in the past and could be a good resource.
We have a few resources referencing the Sasso breed of chicken on ECHOcommunity which may be helpful to you.
Do any network members have direct experience with raising Sasso chickens or where to find them in Nigeria?
I have to inquire, this seems new to me in Nigeria though am from Southern Nigeria (Niger Delta of Nigeria).