strelitzia pot companion

Aerynsun

Hello, first time on this forum and novice gardner! I have been given 2 strelitzia plants which are in pots at the moment in the back garden. They are doing well enough, but I would like to plant them in two big pots to go permenantly in a sunny south facing spot. However I don't want them on their own. Could anyone please help me by giving me some ideas as to what plants I can put with them in the pots? I would like there to be a contrast in design. So the upright of the Strlitzia with flowing around the edges? 

Thank you all in advance.