Hardy Tropicals UK

Evening, I am moving on with my humid biome now. Just need some suggestions for plants to fill this area which measures about 4 x 2 meters. Quite a shady aspect and will be humid and of coarse frost free. I want some height, including some real statement plants, but I can't have anything too busy in front of the living wall. While I will plant in front of it, I want to be able to see through the plants to the living wall backdrop.

The picture was taken at night, so excuse the quality.

First thought was a Lytocaryum weddellianum. The thin delicate fronds on this palm won't impede the view of the living wall.