Mel...
I am Angolan and lived in Luanda.
Maybe what I'll say will not be this perfect because I am not fond at all of the place...
As far as Asians are concerned, we have a huge Korean community, and recently, Chinese workers made their entrance to the sight (mostly, only men). I have no clue about a familyfriendly community. Koreans have been in Angola for so long, that maybe on their side... But I don't know.
Good hospitals... hmm, forget that. There are expensive clinics, but even Angolan people (who can afford it) rather go to South Africa get treated. Our doctors are great, but sadly the conditions are not the best to show off their talent...
With two kids, if you're not used to this kind of urban jungle, you'd rather go to Germany. But then again. Go for a visit. You might actually like it.
You'll have a higher life standard as many of the foreigners have, and that may include an extra car with a driver ;-) It's useful in that city of my father's ;-) (yes, I am not from Luanda, can you tell ? :-P), and you can have a nice life if you put the money in it. It's a very expensive city.
We use US Dollars (if you are paid in Euros, you win) but going to the supermarket, the bill can go up to 200$. Going to dinner in a fancy restaurant, the bill will be the same. To get in a nice pub/disco, you have to pay 20/30$. That's average.
Go and see for yourself as I am not the best guide to the capital (to the bushes maybe, because I love roadtrip in the savana). You might love what I don't :-)