It would be best to confirm all this with a home renting company in Angola, but a foreigner can purchase property in Angola, its just very expensice, average of 5 hundred thousand - 1 mil USD per apartment or house. And the average rent you can ask will be from about 10000 - 25000 USD per month depending on the location and the condition of the property.
Here is a link that might help
http://www.propertyfrontiers.com/resear … ofile.aspx
You can also try their private investment organization.
http://www.anip.co.ao/Default.aspx?lang=en-US
But I would rather get a Visa for Angola and go stay there for a week and scope out the city and Talatona before just diving in and buying any old property because it sounds good, there are many upon many blocks of apartment in Talatona standing open for a few years now without any renters inside because the local people have built to many places for the demand.
So just be carefull about the property market also, your best bet would be to find a nice house in the city areas like Miramar, Ingombota and Mianga. But Miramar is like prime spot since this is a very nice area and many embassies are setup here and close to the beach, Escola and some shops. Its also rather save here since Police patrol this area quite allot in an effort to gaurd the embassies and schools close by.
I hope you all the best in your searches.