Awning sizing advice

DJM66

Hi, just after a bit of advice on awnings - I have an Elddis Odyssey 462 and am looking to buy a full awning - does anyone know which size I should use - doesn't seem to say in handbook.

Also considering as an alternative an air awning but am concerned about stuff I've read that they don't sit right on uneven ground. Has anyone had experience of this good/bad?

 

Thank  you