If you have already reserved then you have which building you will actually be in since you must choose building at time of reservation. Our preferred area at Jambo is on the Arusha savanna along Zebra trail (the inner right side of the U-shaped building) but you will see animals at any of the savannas. We like Zebra trail because most rooms face west and thus you do not get the sun beeming in during the morning but get to watch the sunset.
As to Kidani, most savanna view rooms are on the Sunset savanna which is to the east of the building but because of the building shape you can be facing east, or somewhat to the north or south depending on location of room. Would recommend there simply asking for room with Sunset Savanna view close to the lobby, both for seeing animals and to avoid the endless walk down the hallway to nowhere (if you get a room at the end of the north wing far from the lobby you will be more than 1/4 mile from the lobby).
