You can add a request (not guaranteed) to your reservation for any of the three savannas, Arusha, Uzima, and Sunset. All rooms are on 5th floor except around the lobby area where a 6th floor exists and it is the AKV conceirge rooms. Otherwise the 5th floor is the top floor throughout the resort.
Arusha is the savanna that is within the U of the U-shaped Jambo building. That is a fine savanna and is a safe bet as a request because view is good from every room. The Sunset is on the left side of that U and Uzima on the right. Most rooms there are fine too for a view except that sunset and uzima have two large on the ground viewing areas for guests and if you get one of the few rooms overlooking that viewing area you do not get as good a view of the savannas. Also, right now, the view across the sunset savanna is at the Kidani construction and thus many desire to avoid that for now. Thus, I would recommend requesting the safe bet for now -- Arusha.