My vote is for Provia 100 / Velvia 100 for safari except for evenings. For family use mix of Provia and Portra 400 for and Portra would be handy for evening safari shots. For macro, you might need more speed so Portra will be a good choice or for more saturation use Ektar/provia. For landscapes use Provia, Velvia 100/50 or Ektar. If possible carry second small body (FM/FG/FE) with macro lens so that you can load one with negative and another with slide film. This way you also get a back up body if either goes kaput. If planning to shoot lot of touristy photos you might go with some consumer negative films like Kodak gold.
Try to take 400mm, 200 might be limiting somewhat especially for birds and small animals. It would suck big time to go all the way there, spot a lion(ess) and not have a decent photo. Especially your family members would like to show their/your friends what they saw in Africa. Just saying.