type of plant to cover a wall

Escallonia, but don't choose one of the big varieties - there's one called Red Elf that only gets about 7 to 8 feet, and there is one even shorter, gets about 6 feet, but I can't remember the name of the variety. I suggest not using ones like "Apple blossom" because its going to be in a container, and that will mean restriction at the roots, which will mean the plant won't be happy not being able to get as big as it wants. You will need a large container, say 18 to 24 inches deep by 18 inches wide anyway, for a permanent shrub there. Escallonia is wind and salt resistant, a good coastal shrub, evergreen, flowers in May/June. You could put a variegated Euonymus in the tub too to sprawl down the front of it (this is a wind and salt resistant one too).
Alternatives: Climbing hydrangea, Cotoneaster varieties (choose carefully, some are evergreen, some not, some get huge, some are only 2 inches high)

How about Garrya elliptica. It is evergreen and has long grey tassels in winter, It responds well to pruning too.

I like Garrya a lot, but it can be frost sensitive through the roots if its in a container. But perhaps where you live, you don't get much frost anyway!

you may consider a pasiflora, passion fruit.