Hi. I am maybe a bit late, but I woul like to add my 5 cents here.

Africa is huge ! It just couldn't be compared with Portugal.

So it depending on whether you want to do a safari or just feel the Afro vibe in Western Africa (which I doubt :) ), you will have to carefully consider the options, because I see a lot more than two :)

Anyway, I recommend you to visit Eastern Africa. I believe it represents a good mix of African lifestyle and nature beauty.

Good Luck!