Really depends on what you want. With african cichlids you're gonna be looking at an overstocked tank with a lot of rocky decor and high pH. you won't be able to keep a whole lot others with africans.
With Central and South Americans, you'll be looking at a more neutral pH, with fewer amounts of fish, but more options for tank mates that aren't cichlids.
I can not decide between South and Central American. I have both, but would probably lean towards Central, as I love my Jack Dempsey. She has such an individual personality, which is a common trait amongst most Central American Cichlids.