Where to buy big white planting troughs

[chih]

I want some big planters for next to my fence. Ideally polyterrazo or such like

Where is the best place to get the

Alternatively could I pay a bricky to build a wall on the patio and render it and paint it white?

A bit clueless sorry

IME planters are v expensive .It could be that building out of breeze blocks and rendering and painting would be cheaper.