I thought the rooms start at the 3rd floor @ Jambo, but I could be wrong.
If you have a savanna view and want eye level w/ a giraffe then a lower floor is better. But, unless you are staying in a villa, you'll be on a lower floor, anyway. There are 2 savanna view categories, Arusha (the middle savanna) which is more expensive than just plain savanna view.
I think the pool view rooms are worth the extra $10 or so a night over standard view- ask for Zebra trail as that puts you right by the elevators that go down to the pool, the Mara (fast food) & the kids play area. The other pool rooms are on Giraffe trail (which also has standard view rooms,) and the Giraffe trail rooms do have the advantage of a secret door that cuts down on the walk to/from the bus.
If you opt for savannah view, asking for Uzima on Zebra trail puts you on the pool/food side. If Arusha Savannah view, asking for Zebra trail again puts you by the pool/food side.
The other side is Kudu trail and a bit of a hike to the pool/food or Ostrich trail. Kudu trail rooms face either Arusha savana or Sunset savanna. Ostrich trail rooms face sunset savanna or are standard view.
If it's not a budget buster I'd splurge for a savanna view (but personally wouldn't pay extra for Arusha savanna.) Although the pool views are quite pretty, IMO, just no animals from the balcony.
Here's a map:
http://dvcnews.com/index.php/resorts/animal-kingdom-villas/maps-a-photos - click on the first map 'Jambo'
It's for the villas on the upper floors, so the numbers are different, but it gives you an idea of the layout of the resort.