The plant they mean is actually Metrosideros excelsa, and its good in coastal areas, reasonably tolerant of salt spray. Height and spread in areas with appropriate climate conditions (its a tender plant) up to 20m by 15m spread. However, in a pot, its growth will be restricted, depending on the size of the pot. Even in a large pot (say, 3 feet deep and 2 feet wide) it will never make its ultimate height and spread - but if you do use a large pot (eventually, don't use a pot more than 3 times the size of the rootball initially) it will get, if you're lucky, a third to a half in height and spread.

I have both, and the Metrosideros I have is about 80' tall. It is also known as the New Zealand Christmas tree because it flowers down there in December. 6 months later, mine flowers. The roots are agressive, and they hang down from branches as well!
The Euonymous I have is a green and white varigated, and gets huge if not regularly pruned.
You might try Plumbago (easy to start from seed). Pittosporum undulatum would work (I use it as a wind break).
Norfolk pine is a slow grower.
Any salts in the water should wash out in winter when it rains.

In the ground, maybe, Wylie, but not so much in pots...

The roots on the Metrosideros are massive and I think they would burst the pot. In the ground, they push the rock walls around, so no telling what they would do in a pot. On the other hand, they take pruning very well. I have a neighbor who uses them as a wind barrier as a hedge.