To some extent it might depend upon the brand and model and age of awning you have at present and where it's attached to the Troll i.e. awning rail or roof.
On many awnings of the type you describe you can buy sides and fronts that convert it to a full awning.
If you don't fancy that then a preference for air beam or solid framework will help and whether you'd prefer a lightweight pop-up type awning that's popular with campervan types or a full thicker fabric, heavier type used by WWB's.