I just happened to see your thread. Not sure if it still applies to you. I know that Kenya Airways has two foreign crew bases: Accra, Ghana and Bangkok, Thailand.
They currently have about 64 foreign crew members, but these were nationals of Thailand, Ghana, and Cameroon. You can always find out if you're eligible to apply. try their website, and then look for the job portal for current openings, or drop them an email from the address provided on the job portal.
Kenya Airways: The Pride of Africa
Can't say much about Ethiopian Airlines, I'm afraid. I don't know as much about them.
All the best