Yes, upper berth. Look at deck plans though. I always try to get one near the centrum and elevators on as high a deck as possible. On this ship deck 8,9 or 10.
To your question about which is better. The ones that enter from the end i.e., the door is between the closet and bathroom as opposed to on the side have better usable space and a larger couch. With the door on the side there is only a chair.
The cabins for three are no bigger than for two. I would try and get one that can accommodate 4. They you will have two bunks and the two on the floor can be made into a queen.
You can tell by the deck plan which they are with a cross instead of an asterik.
For example 1555 or 1255 are near forward atrium and have 4 beds.